
/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.07e                    (C)ChaN, 2009
/-----------------------------------------------------------------------------/
/ FatFs module is a generic FAT file system module for small embedded systems.
/ This is a free software that opened for education, research and commercial
/ developments under license policy of following trems.
/
/  Copyright (C) 2009, ChaN, all right reserved.
/
/ * The FatFs module is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-----------------------------------------------------------------------------/
/ Feb 26,'06 R0.00  Prototype.
/
/ Apr 29,'06 R0.01  First stable version.
/
/ Jun 01,'06 R0.02  Added FAT12 support.
/                   Removed unbuffered mode.
/                   Fixed a problem on small (<32M) patition.
/ Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
/
/ Sep 22,'06 R0.03  Added f_rename().
/                   Changed option _FS_MINIMUM to _FS_MINIMIZE.
/ Dec 11,'06 R0.03a Improved cluster scan algolithm to write files fast.
/                   Fixed f_mkdir() creates incorrect directory on FAT32.
/
/ Feb 04,'07 R0.04  Supported multiple drive system.
/                   Changed some interfaces for multiple drive system.
/                   Changed f_mountdrv() to f_mount().
/                   Added f_mkfs().
/ Apr 01,'07 R0.04a Supported multiple partitions on a plysical drive.
/                   Added a capability of extending file size to f_lseek().
/                   Added minimization level 3.
/                   Fixed an endian sensitive code in f_mkfs().
/ May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
/                   Added FSInfo support.
/                   Fixed DBCS name can result FR_INVALID_NAME.
/                   Fixed short seek (<= csize) collapses the file object.
/
/ Aug 25,'07 R0.05  Changed arguments of f_read(), f_write() and f_mkfs().
/                   Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
/                   Fixed f_mkdir() on FAT32 creates incorrect directory.
/ Feb 03,'08 R0.05a Added f_truncate() and f_utime().
/                   Fixed off by one error at FAT sub-type determination.
/                   Fixed btr in f_read() can be mistruncated.
/                   Fixed cached sector is not flushed when create and close
/                   without write.
/
/ Apr 01,'08 R0.06  Added fputc(), fputs(), fprintf() and fgets().
/                   Improved performance of f_lseek() on moving to the same
/                   or following cluster.
/
/ Apr 01,'09 R0.07  Merged Tiny-FatFs as a buffer configuration option.
/                   Added long file name support.
/                   Added multiple code page support.
/                   Added re-entrancy for multitask operation.
/                   Added auto cluster size selection to f_mkfs().
/                   Added rewind option to f_readdir().
/                   Changed result code of critical errors.
/                   Renamed string functions to avoid name collision.
/ Apr 14,'09 R0.07a Separated out OS dependent code on reentrant cfg.
/                   Added multiple sector size support.
/ Jun 21,'09 R0.07c Fixed f_unlink() can return FR_OK on error.
/                   Fixed wrong cache control in f_lseek().
/                   Added relative path feature.
/                   Added f_chdir() and f_chdrive().
/                   Added proper case conversion to extended char.
/ Nov 03,'09 R0.07e Separated out configuration options from ff.h to ffconf.h.
/                   Fixed f_unlink() fails to remove a sub-dir on _FS_RPATH.
/                   Fixed name matching error on the 13 char boundary.
/                   Added a configuration option, _LFN_UNICODE.
/                   Changed f_readdir() to return the SFN with always upper
/                   case on non-LFN cfg.
/---------------------------------------------------------------------------*/

#include "ff.h"                 /* FatFs configurations and declarations */
#include "diskio.h"             /* Declarations of low level disk I/O functions */

/*--------------------------------------------------------------------------

   Module Private Definitions

---------------------------------------------------------------------------*/

#if _FATFS != 0x007E
#error Wrong include file (ff.h).
#endif

#if _FS_REENTRANT
#if _USE_LFN == 1
#error Static LFN work area must not be used in re-entrant configuration.
#endif
#define	ENTER_FF(fs)		{ if (!lock_fs(fs)) return FR_TIMEOUT; }
#define	LEAVE_FF(fs, res)	{ unlock_fs(fs, res); return res; }

#else
#define	ENTER_FF(fs)
#define LEAVE_FF(fs, res)	return res

#endif

#define	ABORT(fs, res)		{ fp->flag |= FA__ERROR; LEAVE_FF(fs, res); }

#ifndef NULL
#define	NULL	0
#endif

/* Name status flags */
#define NS			11          /* Offset of name status byte */
#define NS_LOSS		0x01        /* Out of 8.3 format */
#define NS_LFN		0x02        /* Force to create LFN entry */
#define NS_LAST		0x04        /* Last segment */
#define NS_BODY		0x08        /* Lower case flag (body) */
#define NS_EXT		0x10        /* Lower case flag (ext) */
#define NS_DOT		0x20        /* Dot entry */

/*--------------------------------------------------------------------------

   Private Work Area

---------------------------------------------------------------------------*/

#if _DRIVES < 1 || _DRIVES > 9
#error Number of drives must be 1-9.
#endif
static FATFS *FatFs[_DRIVES];   /* Pointer to the file system objects (logical drives) */

static WORD Fsid;               /* File system mount ID */

#if _FS_RPATH
static BYTE Drive;              /* Current drive */
#endif

#if _USE_LFN == 1               /* LFN with static LFN working buffer */
static WCHAR LfnBuf[_MAX_LFN + 1];

#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR *lp = LfnBuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#elif _USE_LFN > 1              /* LFN with dynamic LFN working buffer */
#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR lbuf[_MAX_LFN + 1], *lp = lbuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#else /* No LFN */
#define	NAMEBUF(sp,lp)	BYTE sp[12]
#define INITBUF(dj,sp,lp)	dj.fn = sp

#endif

/*--------------------------------------------------------------------------

   Module Private Functions

---------------------------------------------------------------------------*/

/*-----------------------------------------------------------------------*/

/* String functions                                                      */

/*-----------------------------------------------------------------------*/

/* Copy memory to memory */
static void mem_cpy (void *dst, const void *src, int cnt)
{
    char *d = (char *)dst;
    const char *s = (const char *)src;

    while (cnt--)
        *d++ = *s++;
}

/* Fill memory */
static void mem_set (void *dst, int val, int cnt)
{
    char *d = (char *)dst;

    while (cnt--)
        *d++ = (char)val;
}

/* Compare memory to memory */
static int mem_cmp (const void *dst, const void *src, int cnt)
{
    const char *d = (const char *)dst, *s = (const char *)src;
    int r = 0;

    while (cnt-- && (r = *d++ - *s++) == 0) ;
    return r;
}

/* Check if chr is contained in the string */
static int chk_chr (const char *str, int chr)
{
    while (*str && *str != chr)
        str++;
    return *str;
}

/*-----------------------------------------------------------------------*/

/* Request/Release grant to access the volume                            */

/*-----------------------------------------------------------------------*/
#if _FS_REENTRANT

static BOOL lock_fs (FATFS * fs /* File system object */
    )
{
    return ff_req_grant (fs->sobj);
}

static void unlock_fs (FATFS * fs,  /* File system object */
                       FRESULT res  /* Result code to be returned */
    )
{
    if (res != FR_NOT_ENABLED &&
        res != FR_INVALID_DRIVE &&
        res != FR_INVALID_OBJECT && res != FR_TIMEOUT)
    {
        ff_rel_grant (fs->sobj);
    }
}
#endif

/*-----------------------------------------------------------------------*/

/* Change window offset                                                  */

/*-----------------------------------------------------------------------*/

static FRESULT move_window (FATFS * fs, /* File system object */
                            DWORD sector    /* Sector number to make apperance in the fs->win[] */
                            )/* Move to zero only writes back dirty window */
{
    DWORD wsect;

    wsect = fs->winsect;
    if (wsect != sector)
    {                           /* Changed current window */
#if !_FS_READONLY
        if (fs->wflag)
        {                       /* Write back dirty window if needed */
            if (disk_write (fs->drive, fs->win, wsect, 1) != RES_OK)
                return FR_DISK_ERR;
            fs->wflag = 0;
            if (wsect < (fs->fatbase + fs->sects_fat))
            {                   /* In FAT area */
                BYTE nf;

                for (nf = fs->n_fats; nf > 1; nf--)
                {               /* Refrect the change to all FAT copies */
                    wsect += fs->sects_fat;
                    disk_write (fs->drive, fs->win, wsect, 1);
                }
            }
        }
#endif
        if (sector)
        {
            if (disk_read (fs->drive, fs->win, sector, 1) != RES_OK)
                return FR_DISK_ERR;
            fs->winsect = sector;
        }
    }

    return FR_OK;
}

/*-----------------------------------------------------------------------*/

/* Clean-up cached data                                                  */
/* IN FATFS*       File system object */
/* FR_OK: successful, FR_DISK_ERR: failed */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static FRESULT sync ( FATFS * fs)
{
    FRESULT res;

    res = move_window (fs, 0);
    if (res == FR_OK)
    {
        /* Update FSInfo sector if needed */
        if (fs->fs_type == FS_FAT32 && fs->fsi_flag)
        {
            fs->winsect = 0;
            mem_set (fs->win, 0, 512);
            ST_WORD (fs->win + BS_55AA, 0xAA55);
            ST_DWORD (fs->win + FSI_LeadSig, 0x41615252);
            ST_DWORD (fs->win + FSI_StrucSig, 0x61417272);
            ST_DWORD (fs->win + FSI_Free_Count, fs->free_clust);
            ST_DWORD (fs->win + FSI_Nxt_Free, fs->last_clust);
            disk_write (fs->drive, fs->win, fs->fsi_sector, 1);
            fs->fsi_flag = 0;
        }
        /* Make sure that no pending write process in the physical drive */
        if (disk_ioctl (fs->drive, CTRL_SYNC, (void *)NULL) != RES_OK)
            res = FR_DISK_ERR;
    }

    return res;
}
#endif

/*-----------------------------------------------------------------------*/

/* FAT access - Read value of a FAT entry                                */

/*-----------------------------------------------------------------------*/

DWORD get_fat (                 /* 0xFFFFFFFF:Disk error, 1:Interal error, Else:Cluster status */
                  FATFS * fs,   /* File system object */
                  DWORD clst    /* Cluster# to get the link information */
    )
{
    UINT wc, bc;
    DWORD fsect;

    if (clst < 2 || clst >= fs->max_clust)  /* Range check */
        return 1;

    fsect = fs->fatbase;
    switch (fs->fs_type)
    {
        case FS_FAT12:
            bc = clst;
            bc += bc / 2;
            if (move_window (fs, fsect + (bc / SS (fs))))
                break;
            wc = fs->win[bc & (SS (fs) - 1)];
            bc++;
            if (move_window (fs, fsect + (bc / SS (fs))))
                break;
            wc |= (WORD) fs->win[bc & (SS (fs) - 1)] << 8;
            return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);

        case FS_FAT16:
            if (move_window (fs, fsect + (clst / (SS (fs) / 2))))
                break;
            return LD_WORD (&fs->win[((WORD) clst * 2) & (SS (fs) - 1)]);

        case FS_FAT32:
            if (move_window (fs, fsect + (clst / (SS (fs) / 4))))
                break;
            return LD_DWORD (&fs->
                             win[((WORD) clst * 4) & (SS (fs) -
                                                      1)]) & 0x0FFFFFFF;
    }

    return 0xFFFFFFFF;          /* An error occured at the disk I/O layer */
}

/*-----------------------------------------------------------------------*/

/* FAT access - Change value of a FAT entry                              */

/*-----------------------------------------------------------------------*/
#if !_FS_READONLY

FRESULT put_fat (FATFS * fs,    /* File system object */
                 DWORD clst,    /* Cluster# to be changed in range of 2 to fs->max_clust - 1 */
                 DWORD val      /* New value to mark the cluster */
    )
{
    UINT bc;
    BYTE *p;
    DWORD fsect;
    FRESULT res;

    if (clst < 2 || clst >= fs->max_clust)
    {                           /* Range check */
        res = FR_INT_ERR;

    }
    else
    {
        fsect = fs->fatbase;
        switch (fs->fs_type)
        {
            case FS_FAT12:
                bc = clst;
                bc += bc / 2;
                res = move_window (fs, fsect + (bc / SS (fs)));
                if (res != FR_OK)
                    break;
                p = &fs->win[bc & (SS (fs) - 1)];
                *p = (clst & 1) ? ((*p & 0x0F) | ((BYTE) val << 4)) : (BYTE)
                    val;
                bc++;
                fs->wflag = 1;
                res = move_window (fs, fsect + (bc / SS (fs)));
                if (res != FR_OK)
                    break;
                p = &fs->win[bc & (SS (fs) - 1)];
                *p = (clst & 1) ? (BYTE) (val >> 4) : ((*p & 0xF0) |
                                                       ((BYTE) (val >> 8) &
                                                        0x0F));
                break;

            case FS_FAT16:
                res = move_window (fs, fsect + (clst / (SS (fs) / 2)));
                if (res != FR_OK)
                    break;
                ST_WORD (&fs->win[((WORD) clst * 2) & (SS (fs) - 1)],
                         (WORD) val);
                break;

            case FS_FAT32:
                res = move_window (fs, fsect + (clst / (SS (fs) / 4)));
                if (res != FR_OK)
                    break;
                ST_DWORD (&fs->win[((WORD) clst * 4) & (SS (fs) - 1)], val);
                break;

            default:
                res = FR_INT_ERR;
        }
        fs->wflag = 1;
    }

    return res;
}
#endif /* !_FS_READONLY */

/*-----------------------------------------------------------------------*/

/* FAT handling - Remove a cluster chain                                 */

/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static FRESULT remove_chain (FATFS * fs,    /* File system object */
                             DWORD clst /* Cluster# to remove a chain from */
    )
{
    FRESULT res;
    DWORD nxt;

    if (clst < 2 || clst >= fs->max_clust)
    {                           /* Check the range of cluster# */
        res = FR_INT_ERR;

    }
    else
    {
        res = FR_OK;
        while (clst < fs->max_clust)
        {                       /* Not a last link? */
            nxt = get_fat (fs, clst);   /* Get cluster status */
            if (nxt == 0)
                break;          /* Empty cluster? */
            if (nxt == 1)
            {
                res = FR_INT_ERR;
                break;
            }                   /* Internal error? */
            if (nxt == 0xFFFFFFFF)
            {
                res = FR_DISK_ERR;
                break;
            }                   /* Disk error? */
            res = put_fat (fs, clst, 0);    /* Mark the cluster "empty" */
            if (res != FR_OK)
                break;
            if (fs->free_clust != 0xFFFFFFFF)
            {                   /* Update FSInfo */
                fs->free_clust++;
                fs->fsi_flag = 1;
            }
            clst = nxt;         /* Next cluster */
        }
    }

    return res;
}
#endif

/*-----------------------------------------------------------------------*/

/* FAT handling - Stretch or Create a cluster chain                      */

/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static DWORD create_chain (     /* 0:No free cluster, 1:Internal error, 0xFFFFFFFF:Disk error, >=2:New cluster# */
                              FATFS * fs,   /* File system object */
                              DWORD clst    /* Cluster# to stretch. 0 means create a new chain. */
    )
{
    DWORD cs, ncl, scl, mcl;

    mcl = fs->max_clust;
    if (clst == 0)
    {                           /* Create new chain */
        scl = fs->last_clust;   /* Get suggested start point */
        if (scl == 0 || scl >= mcl)
            scl = 1;
    }
    else
    {                           /* Stretch existing chain */
        cs = get_fat (fs, clst);    /* Check the cluster status */
        if (cs < 2)
            return 1;           /* It is an invalid cluster */
        if (cs < mcl)
            return cs;          /* It is already followed by next cluster */
        scl = clst;
    }

    ncl = scl;                  /* Start cluster */
    for (;;)
    {
        ncl++;                  /* Next cluster */
        if (ncl >= mcl)
        {                       /* Wrap around */
            ncl = 2;
            if (ncl > scl)
                return 0;       /* No free custer */
        }
        cs = get_fat (fs, ncl); /* Get the cluster status */
        if (cs == 0)
            break;              /* Found a free cluster */
        if (cs == 0xFFFFFFFF || cs == 1)    /* An error occured */
            return cs;
        if (ncl == scl)
            return 0;           /* No free custer */
    }

    if (put_fat (fs, ncl, 0x0FFFFFFF))  /* Mark the new cluster "in use" */
        return 0xFFFFFFFF;
    if (clst != 0)
    {                           /* Link it to the previous one if needed */
        if (put_fat (fs, clst, ncl))
            return 0xFFFFFFFF;
    }

    fs->last_clust = ncl;       /* Update FSINFO */
    if (fs->free_clust != 0xFFFFFFFF)
    {
        fs->free_clust--;
        fs->fsi_flag = 1;
    }

    return ncl;                 /* Return new cluster number */
}
#endif /* !_FS_READONLY */

/*-----------------------------------------------------------------------*/

/* Get sector# from cluster#                                             */

/*-----------------------------------------------------------------------*/

DWORD clust2sect (              /* !=0: Sector number, 0: Failed - invalid cluster# */
                     FATFS * fs,    /* File system object */
                     DWORD clst /* Cluster# to be converted */
    )
{
    clst -= 2;
    if (clst >= (fs->max_clust - 2))
        return 0;               /* Invalid cluster# */
    return clst * fs->csize + fs->database;
}

/*-----------------------------------------------------------------------*/

/* Directory handling - Seek directory index                             */

/*-----------------------------------------------------------------------*/

static FRESULT dir_seek (DIR * dj,  /* Pointer to directory object */
                         WORD idx   /* Directory index number */
    )
{
    DWORD clst;
    WORD ic;

    dj->index = idx;
    clst = dj->sclust;
    if (clst == 1 || clst >= dj->fs->max_clust) /* Check start cluster range */
        return FR_INT_ERR;
    if (!clst && dj->fs->fs_type == FS_FAT32)   /* Replace cluster# 0 with root cluster# if in FAT32 */
        clst = dj->fs->dirbase;

    if (clst == 0)
    {                           /* Static table */
        dj->clust = clst;
        if (idx >= dj->fs->n_rootdir)   /* Index is out of range */
            return FR_INT_ERR;
        dj->sect = dj->fs->dirbase + idx / (SS (dj->fs) / 32);  /* Sector# */
    }
    else
    {                           /* Dynamic table */
        ic = SS (dj->fs) / 32 * dj->fs->csize;  /* Entries per cluster */
        while (idx >= ic)
        {                       /* Follow cluster chain */
            clst = get_fat (dj->fs, clst);  /* Get next cluster */
            if (clst == 0xFFFFFFFF)
                return FR_DISK_ERR; /* Disk error */
            if (clst < 2 || clst >= dj->fs->max_clust)  /* Reached to end of table or int error */
                return FR_INT_ERR;
            idx -= ic;
        }
        dj->clust = clst;
        dj->sect = clust2sect (dj->fs, clst) + idx / (SS (dj->fs) / 32);    /* Sector# */
    }

    dj->dir = dj->fs->win + (idx % (SS (dj->fs) / 32)) * 32;    /* Ptr to the entry in the sector */

    return FR_OK;               /* Seek succeeded */
}

/*-----------------------------------------------------------------------*/

/* Directory handling - Move directory index next                        */

/*-----------------------------------------------------------------------*/

static FRESULT dir_next (       /* FR_OK:Succeeded, FR_NO_FILE:End of table, FR_DENIED:EOT and could not streach */
                            DIR * dj,   /* Pointer to directory object */
                            BOOL streach    /* FALSE: Do not streach table, TRUE: Streach table if needed */
    )
{
    DWORD clst;
    WORD i;

    i = dj->index + 1;
    if (!i || !dj->sect)        /* Report EOT when index has reached 65535 */
        return FR_NO_FILE;

    if (!(i % (SS (dj->fs) / 32)))
    {                           /* Sector changed? */
        dj->sect++;             /* Next sector */

        if (dj->clust == 0)
        {                       /* Static table */
            if (i >= dj->fs->n_rootdir) /* Report EOT when end of table */
                return FR_NO_FILE;
        }
        else
        {                       /* Dynamic table */
            if (((i / (SS (dj->fs) / 32)) & (dj->fs->csize - 1)) == 0)
            {                   /* Cluster changed? */
                clst = get_fat (dj->fs, dj->clust); /* Get next cluster */
                if (clst <= 1)
                    return FR_INT_ERR;
                if (clst == 0xFFFFFFFF)
                    return FR_DISK_ERR;
                if (clst >= dj->fs->max_clust)
                {               /* When it reached end of dynamic table */
#if !_FS_READONLY
                    BYTE c;

                    if (!streach)
                        return FR_NO_FILE;  /* When do not streach, report EOT */
                    clst = create_chain (dj->fs, dj->clust);    /* Streach cluster chain */
                    if (clst == 0)
                        return FR_DENIED;   /* No free cluster */
                    if (clst == 1)
                        return FR_INT_ERR;
                    if (clst == 0xFFFFFFFF)
                        return FR_DISK_ERR;
                    /* Clean-up streached table */
                    if (move_window (dj->fs, 0))
                        return FR_DISK_ERR; /* Flush active window */
                    mem_set (dj->fs->win, 0, SS (dj->fs));  /* Clear window buffer */
                    dj->fs->winsect = clust2sect (dj->fs, clst);    /* Cluster start sector */
                    for (c = 0; c < dj->fs->csize; c++)
                    {           /* Fill the new cluster with 0 */
                        dj->fs->wflag = 1;
                        if (move_window (dj->fs, 0))
                            return FR_DISK_ERR;
                        dj->fs->winsect++;
                    }
                    dj->fs->winsect -= c;   /* Rewind window address */
#else
                    return FR_NO_FILE;  /* Report EOT */
#endif
                }
                dj->clust = clst;   /* Initialize data for new cluster */
                dj->sect = clust2sect (dj->fs, clst);
            }
        }
    }

    dj->index = i;
    dj->dir = dj->fs->win + (i % (SS (dj->fs) / 32)) * 32;

    return FR_OK;
}

/*-----------------------------------------------------------------------*/

/* LFN handling - Test/Pick/Fit an LFN segment from/to directory entry   */

/*-----------------------------------------------------------------------*/
#if _USE_LFN
static const BYTE LfnOfs[] = { 1, 3, 5, 7, 9, 14, 16, 18, 20, 22, 24, 28, 30 }; /* Offset of LFN chars in the directory entry */

static BOOL cmp_lfn (           /* TRUE:Matched, FALSE:Not matched */
                        WCHAR * lfnbuf, /* Pointer to the LFN to be compared */
                        BYTE * dir  /* Pointer to the directory entry containing a part of LFN */
    )
{
    int i, s;
    WCHAR wc, uc;

    i = ((dir[LDIR_Ord] & 0xBF) - 1) * 13;  /* Get offset in the LFN buffer */
    s = 0;
    wc = 1;
    do
    {
        uc = LD_WORD (dir + LfnOfs[s]); /* Pick an LFN character from the entry */
        if (wc)
        {                       /* Last char has not been processed */
            wc = ff_wtoupper (uc);  /* Convert it to upper case */
            if (i >= _MAX_LFN || wc != ff_wtoupper (lfnbuf[i++]))   /* Compare it */
                return FALSE;   /* Not matched */
        }
        else
        {
            if (uc != 0xFFFF)
                return FALSE;   /* Check filler */
        }
    } while (++s < 13);         /* Repeat until all chars in the entry are checked */

    if ((dir[LDIR_Ord] & 0x40) && wc && lfnbuf[i])  /* Last segment matched but different length */
        return FALSE;

    return TRUE;                /* The part of LFN matched */
}

static BOOL pick_lfn (          /* TRUE:Succeeded, FALSE:Buffer overflow */
                         WCHAR * lfnbuf,    /* Pointer to the Unicode-LFN buffer */
                         BYTE * dir /* Pointer to the directory entry */
    )
{
    int i, s;
    WCHAR wc, uc;

    i = ((dir[LDIR_Ord] & 0x3F) - 1) * 13;  /* Offset in the LFN buffer */

    s = 0;
    wc = 1;
    do
    {
        uc = LD_WORD (dir + LfnOfs[s]); /* Pick an LFN character from the entry */
        if (wc)
        {                       /* Last char has not been processed */
            if (i >= _MAX_LFN)
                return FALSE;   /* Buffer overflow? */
            lfnbuf[i++] = wc = uc;  /* Store it */
        }
        else
        {
            if (uc != 0xFFFF)
                return FALSE;   /* Check filler */
        }
    } while (++s < 13);         /* Read all character in the entry */

    if (dir[LDIR_Ord] & 0x40)
    {                           /* Put terminator if it is the last LFN part */
        if (i >= _MAX_LFN)
            return FALSE;       /* Buffer overflow? */
        lfnbuf[i] = 0;
    }

    return TRUE;
}

#if !_FS_READONLY
static void fit_lfn (const WCHAR * lfnbuf,  /* Pointer to the LFN buffer */
                     BYTE * dir,    /* Pointer to the directory entry */
                     BYTE ord,  /* LFN order (1-20) */
                     BYTE sum   /* SFN sum */
    )
{
    int i, s;
    WCHAR wc;

    dir[LDIR_Chksum] = sum;     /* Set check sum */
    dir[LDIR_Attr] = AM_LFN;    /* Set attribute. LFN entry */
    dir[LDIR_Type] = 0;
    ST_WORD (dir + LDIR_FstClusLO, 0);

    i = (ord - 1) * 13;         /* Get offset in the LFN buffer */
    s = wc = 0;
    do
    {
        if (wc != 0xFFFF)
            wc = lfnbuf[i++];   /* Get an effective char */
        ST_WORD (dir + LfnOfs[s], wc);  /* Put it */
        if (!wc)
            wc = 0xFFFF;        /* Padding chars following last char */
    } while (++s < 13);
    if (wc == 0xFFFF || !lfnbuf[i])
        ord |= 0x40;            /* Bottom LFN part is the start of LFN sequence */
    dir[LDIR_Ord] = ord;        /* Set the LFN order */
}

#endif
#endif

/*-----------------------------------------------------------------------*/

/* Create numbered name                                                  */

/*-----------------------------------------------------------------------*/
#if _USE_LFN
void gen_numname (BYTE * dst,   /* Pointer to genartated SFN */
                  const BYTE * src, /* Pointer to source SFN to be modified */
                  const WCHAR * lfn,    /* Pointer to LFN */
                  WORD num      /* Sequense number */
    )
{
    char ns[8];
    int i, j;

    mem_cpy (dst, src, 11);

    if (num > 5)
    {                           /* On many collisions, generate a hash number instead of sequencial number */
        do
            num = (num >> 1) + (num << 15) + (WORD) * lfn++;
        while (*lfn);
    }

    /* itoa */
    i = 7;
    do
    {
        ns[i--] = (num % 10) + '0';
        num /= 10;
    } while (num);
    ns[i] = '~';

    /* Append the number */
    for (j = 0; j < i && dst[j] != ' '; j++)
    {
        if (IsDBCS1 (dst[j]))
        {
            if (j == i - 1)
                break;
            j++;
        }
    }
    do
    {
        dst[j++] = (i < 8) ? ns[i++] : ' ';
    } while (j < 8);
}
#endif

/*-----------------------------------------------------------------------*/

/* Calculate sum of an SFN                                               */

/*-----------------------------------------------------------------------*/
#if _USE_LFN
static BYTE sum_sfn (const BYTE * dir   /* Ptr to directory entry */
    )
{
    BYTE sum = 0;
    int n = 11;

    do
        sum = (sum >> 1) + (sum << 7) + *dir++;
    while (--n);
    return sum;
}
#endif

/*-----------------------------------------------------------------------*/

/* Directory handling - Find an object in the directory                  */

/*-----------------------------------------------------------------------*/

static FRESULT dir_find (DIR * dj   /* Pointer to the directory object linked to the file name */
    )
{
    FRESULT res;
    BYTE c, *dir;

#if _USE_LFN
    BYTE a, ord, sum;
#endif

    res = dir_seek (dj, 0);     /* Rewind directory object */
    if (res != FR_OK)
        return res;

#if _USE_LFN
    ord = sum = 0xFF;
#endif
    do
    {
        res = move_window (dj->fs, dj->sect);
        if (res != FR_OK)
            break;
        dir = dj->dir;          /* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if (c == 0)
        {
            res = FR_NO_FILE;
            break;
        }                       /* Reached to end of table */
#if _USE_LFN                    /* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if (c == 0xE5 || ((a & AM_VOL) && a != AM_LFN))
        {                       /* An entry without valid data */
            ord = 0xFF;
        }
        else
        {
            if (a == AM_LFN)
            {                   /* An LFN entry is found */
                if (dj->lfn)
                {
                    if (c & 0x40)
                    {           /* Is it start of LFN sequence? */
                        sum = dir[LDIR_Chksum];
                        c &= 0xBF;
                        ord = c;    /* LFN start order */
                        dj->lfn_idx = dj->index;
                    }
                    /* Check validity of the LFN entry and compare it with given name */
                    ord = (c == ord && sum == dir[LDIR_Chksum] &&
                           cmp_lfn (dj->lfn, dir)) ? ord - 1 : 0xFF;
                }
            }
            else
            {                   /* An SFN entry is found */
                if (!ord && sum == sum_sfn (dir))
                    break;      /* LFN matched? */
                ord = 0xFF;
                dj->lfn_idx = 0xFFFF;   /* Reset LFN sequence */
                if (!(dj->fn[NS] & NS_LOSS) && !mem_cmp (dir, dj->fn, 11))
                    break;      /* SFN matched? */
            }
        }
#else /* Non LFN configuration */
        if (!(dir[DIR_Attr] & AM_VOL) && !mem_cmp (dir, dj->fn, 11))    /* Is it a valid entry? */
            break;
#endif
        res = dir_next (dj, FALSE); /* Next entry */
    } while (res == FR_OK);

    return res;
}

/*-----------------------------------------------------------------------*/

/* Read an object from the directory                                     */

/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
static FRESULT dir_read (DIR * dj   /* Pointer to the directory object that pointing the entry to be read */
    )
{
    FRESULT res;
    BYTE c, *dir;

#if _USE_LFN
    BYTE a, ord = 0xFF, sum = 0xFF;
#endif

    res = FR_NO_FILE;
    while (dj->sect)
    {
        res = move_window (dj->fs, dj->sect);
        if (res != FR_OK)
            break;
        dir = dj->dir;          /* Ptr to the directory entry of current index */
        c = dir[DIR_Name];
        if (c == 0)
        {
            res = FR_NO_FILE;
            break;
        }                       /* Reached to end of table */
#if _USE_LFN                    /* LFN configuration */
        a = dir[DIR_Attr] & AM_MASK;
        if (c == 0xE5 || (!_FS_RPATH && c == '.') ||
            ((a & AM_VOL) && a != AM_LFN))
        {                       /* An entry without valid data */
            ord = 0xFF;
        }
        else
        {
            if (a == AM_LFN)
            {                   /* An LFN entry is found */
                if (c & 0x40)
                {               /* Is it start of LFN sequence? */
                    sum = dir[LDIR_Chksum];
                    c &= 0xBF;
                    ord = c;
                    dj->lfn_idx = dj->index;
                }
                /* Check LFN validity and capture it */
                ord = (c == ord && sum == dir[LDIR_Chksum] &&
                       pick_lfn (dj->lfn, dir)) ? ord - 1 : 0xFF;
            }
            else
            {                   /* An SFN entry is found */
                if (ord || sum != sum_sfn (dir))    /* Is there a valid LFN? */
                    dj->lfn_idx = 0xFFFF;   /* It has no LFN. */
                break;
            }
        }
#else /* Non LFN configuration */
        if (c != 0xE5 && (_FS_RPATH || c != '.') && !(dir[DIR_Attr] & AM_VOL))  /* Is it a valid entry? */
            break;
#endif
        res = dir_next (dj, FALSE); /* Next entry */
        if (res != FR_OK)
            break;
    }

    if (res != FR_OK)
        dj->sect = 0;

    return res;
}
#endif

/*-----------------------------------------------------------------------*/

/* Register an object to the directory                                   */

/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static FRESULT dir_register (   /* FR_OK:Successful, FR_DENIED:No free entry or too many SFN collision, FR_DISK_ERR:Disk error */
                                DIR * dj    /* Target directory with object name to be created */
    )
{
    FRESULT res;
    BYTE c, *dir;

#if _USE_LFN                    /* LFN configuration */
    WORD n, ne, is;
    BYTE sn[12], *fn, sum;
    WCHAR *lfn;

    fn = dj->fn;
    lfn = dj->lfn;
    mem_cpy (sn, fn, 12);

    if (_FS_RPATH && (sn[NS] & NS_DOT))
        return FR_INVALID_NAME; /* Cannot create dot entry */

    if (sn[NS] & NS_LOSS)
    {                           /* When LFN is out of 8.3 format, generate a numbered name */
        fn[NS] = 0;
        dj->lfn = NULL;         /* Find only SFN */
        for (n = 1; n < 100; n++)
        {
            gen_numname (fn, sn, lfn, n);   /* Generate a numbered name */
            res = dir_find (dj);    /* Check if the name collides with existing SFN */
            if (res != FR_OK)
                break;
        }
        if (n == 100)
            return FR_DENIED;   /* Abort if too many collisions */
        if (res != FR_NO_FILE)
            return res;         /* Abort if the result is other than 'not collided' */
        fn[NS] = sn[NS];
        dj->lfn = lfn;
    }

    if (sn[NS] & NS_LFN)
    {                           /* When LFN is to be created, reserve reserve an SFN + LFN entries. */
        for (ne = 0; lfn[ne]; ne++) ;
        ne = (ne + 25) / 13;
    }
    else
    {                           /* Otherwise reserve only an SFN entry. */
        ne = 1;
    }

    /* Reserve contiguous entries */
    res = dir_seek (dj, 0);
    if (res != FR_OK)
        return res;
    n = is = 0;
    do
    {
        res = move_window (dj->fs, dj->sect);
        if (res != FR_OK)
            break;
        c = *dj->dir;           /* Check the entry status */
        if (c == 0xE5 || c == 0)
        {                       /* Is it a blank entry? */
            if (n == 0)
                is = dj->index; /* First index of the contigulus entry */
            if (++n == ne)
                break;          /* A contiguous entry that requiered count is found */
        }
        else
        {
            n = 0;              /* Not a blank entry. Restart to search */
        }
        res = dir_next (dj, TRUE);  /* Next entry with table streach */
    } while (res == FR_OK);

    if (res == FR_OK && ne > 1)
    {                           /* Initialize LFN entry if needed */
        res = dir_seek (dj, is);
        if (res == FR_OK)
        {
            sum = sum_sfn (dj->fn); /* Sum of the SFN tied to the LFN */
            ne--;
            do
            {                   /* Store LFN entries in bottom first */
                res = move_window (dj->fs, dj->sect);
                if (res != FR_OK)
                    break;
                fit_lfn (dj->lfn, dj->dir, (BYTE) ne, sum);
                dj->fs->wflag = 1;
                res = dir_next (dj, FALSE); /* Next entry */
            } while (res == FR_OK && --ne);
        }
    }

#else /* Non LFN configuration */
    res = dir_seek (dj, 0);
    if (res == FR_OK)
    {
        do
        {                       /* Find a blank entry for the SFN */
            res = move_window (dj->fs, dj->sect);
            if (res != FR_OK)
                break;
            c = *dj->dir;
            if (c == 0xE5 || c == 0)
                break;          /* Is it a blank entry? */
            res = dir_next (dj, TRUE);  /* Next entry with table streach */
        } while (res == FR_OK);
    }
#endif

    if (res == FR_OK)
    {                           /* Initialize the SFN entry */
        res = move_window (dj->fs, dj->sect);
        if (res == FR_OK)
        {
            dir = dj->dir;
            mem_set (dir, 0, 32);   /* Clean the entry */
            mem_cpy (dir, dj->fn, 11);  /* Put SFN */
            dir[DIR_NTres] = *(dj->fn + NS) & (NS_BODY | NS_EXT);   /* Put NT flag */
            dj->fs->wflag = 1;
        }
    }

    return res;
}
#endif /* !_FS_READONLY */

/*-----------------------------------------------------------------------*/

/* Remove an object from the directory                                   */
/* Directory object pointing the entry to be removed */
/* FR_OK: Successful, FR_DISK_ERR: A disk error */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY && !_FS_MINIMIZE
static FRESULT dir_remove (DIR * dj)
{
    FRESULT res;

#if _USE_LFN                    /* LFN configuration */
    WORD i;

    i = dj->index;              /* SFN index */
    res = dir_seek (dj, (WORD) ((dj->lfn_idx == 0xFFFF) ? i : dj->lfn_idx));    /* Goto the SFN or top of the LFN entries */
    if (res == FR_OK)
    {
        do
        {
            res = move_window (dj->fs, dj->sect);
            if (res != FR_OK)
                break;
            *dj->dir = 0xE5;    /* Mark the entry "deleted" */
            dj->fs->wflag = 1;
            if (dj->index >= i)
                break;          /* When reached SFN, all entries of the object has been deleted. */
            res = dir_next (dj, FALSE); /* Next entry */
        } while (res == FR_OK);
        if (res == FR_NO_FILE)
            res = FR_INT_ERR;
    }

#else /* Non LFN configuration */
    res = dir_seek (dj, dj->index);
    if (res == FR_OK)
    {
        res = move_window (dj->fs, dj->sect);
        if (res == FR_OK)
        {
            *dj->dir = 0xE5;    /* Mark the entry "deleted" */
            dj->fs->wflag = 1;
        }
    }
#endif

    return res;
}
#endif /* !_FS_READONLY */

/*-----------------------------------------------------------------------*/

/* Pick a segment and create the object name in directory form           */

/*-----------------------------------------------------------------------*/

static FRESULT create_name (DIR * dj,   /* Pointer to the directory object */
                            const XCHAR ** path /* Pointer to pointer to the segment in the path string */
    )
{
#ifdef _EXCVT
    static const BYTE cvt[] = _EXCVT;
#endif

#if _USE_LFN                    /* LFN configuration */
    BYTE b, cf;
    WCHAR w, *lfn;
    int i, ni, si, di;
    const XCHAR *p;

    /* Create LFN in Unicode */
    si = di = 0;
    p = *path;
    lfn = dj->lfn;
    for (;;)
    {
        w = p[si++];            /* Get a character */
        if (w < ' ' || w == '/' || w == '\\')
            break;              /* Break on end of segment */
        if (di >= _MAX_LFN)     /* Reject too long name */
            return FR_INVALID_NAME;
#if !_LFN_UNICODE
        w &= 0xFF;
        if (IsDBCS1 (w))
        {                       /* If it is a DBC 1st byte */
            b = p[si++];        /* Get 2nd byte */
            if (!IsDBCS2 (b))   /* Reject invalid code for DBC */
                return FR_INVALID_NAME;
            w = (w << 8) + b;
        }
        w = ff_convert (w, 1);  /* Convert OEM to Unicode */
        if (!w)
            return FR_INVALID_NAME; /* Reject invalid code */
#endif
        if (w < 0x80 && chk_chr ("\"*:<>\?|\x7F", w))   /* Reject illegal chars for LFN */
            return FR_INVALID_NAME;
        lfn[di++] = w;          /* Store the Unicode char */
    }
    *path = &p[si];             /* Rerurn pointer to the next segment */
    cf = (w < ' ') ? NS_LAST : 0;   /* Set last segment flag if end of path */
#if _FS_RPATH
    if ((di == 1 && lfn[di - 1] == '.') ||  /* Is this a dot entry? */
        (di == 2 && lfn[di - 1] == '.' && lfn[di - 2] == '.'))
    {
        lfn[di] = 0;
        for (i = 0; i < 11; i++)
            dj->fn[i] = (i < di) ? '.' : ' ';
        dj->fn[i] = cf | NS_DOT;    /* This is a dot entry */
        return FR_OK;
    }
#endif
    while (di)
    {                           /* Strip trailing spaces and dots */
        w = lfn[di - 1];
        if (w != ' ' && w != '.')
            break;
        di--;
    }
    if (!di)
        return FR_INVALID_NAME; /* Reject null string */

    lfn[di] = 0;                /* LFN is created */

    /* Create SFN in directory form */
    mem_set (dj->fn, ' ', 11);
    for (si = 0; lfn[si] == ' ' || lfn[si] == '.'; si++) ;  /* Strip leading spaces and dots */
    if (si)
        cf |= NS_LOSS | NS_LFN;
    while (di && lfn[di - 1] != '.')
        di--;                   /* Find extension (di<=si: no extension) */

    b = i = 0;
    ni = 8;
    for (;;)
    {
        w = lfn[si++];          /* Get an LFN char */
        if (!w)
            break;              /* Break on enf of the LFN */
        if (w == ' ' || (w == '.' && si != di))
        {                       /* Remove spaces and dots */
            cf |= NS_LOSS | NS_LFN;
            continue;
        }

        if (i >= ni || si == di)
        {                       /* Extension or end of SFN */
            if (ni == 11)
            {                   /* Long extension */
                cf |= NS_LOSS | NS_LFN;
                break;
            }
            if (si != di)
                cf |= NS_LOSS | NS_LFN; /* Out of 8.3 format */
            if (si > di)
                break;          /* No extension */
            si = di;
            i = 8;
            ni = 11;            /* Enter extension section */
            b <<= 2;
            continue;
        }

        if (w >= 0x80)
        {                       /* Non ASCII char */
#ifdef _EXCVT
            w = ff_convert (w, 0);  /* Unicode -> OEM code */
            if (w)
                w = cvt[w - 0x80];  /* Convert extended char to upper (SBCS) */
#else
            w = ff_convert (ff_wtoupper (w), 0);    /* Upper converted Unicode -> OEM code */
#endif
            cf |= NS_LFN;       /* Force create LFN entry */
        }

        if (_DF1S && w >= 0x100)
        {                       /* Double byte char */
            if (i >= ni - 1)
            {
                cf |= NS_LOSS | NS_LFN;
                i = ni;
                continue;
            }
            dj->fn[i++] = (BYTE) (w >> 8);
        }
        else
        {                       /* Single byte char */
            if (!w || chk_chr ("+,;[=]", w))
            {                   /* Replace illegal chars for SFN */
                w = '_';
                cf |= NS_LOSS | NS_LFN; /* Lossy conversion */
            }
            else
            {
                if (IsUpper (w))
                {               /* ASCII large capital */
                    b |= 2;
                }
                else
                {
                    if (IsLower (w))
                    {           /* ASCII small capital */
                        b |= 1;
                        w -= 0x20;
                    }
                }
            }
        }
        dj->fn[i++] = (BYTE) w;
    }

    if (dj->fn[0] == 0xE5)
        dj->fn[0] = 0x05;       /* If the first char collides with deleted mark, replace it with 0x05 */

    if (ni == 8)
        b <<= 2;
    if ((b & 0x0C) == 0x0C || (b & 0x03) == 0x03)   /* Create LFN entry when there are composite capitals */
        cf |= NS_LFN;
    if (!(cf & NS_LFN))
    {                           /* When LFN is in 8.3 format without extended char, NT flags are created */
        if ((b & 0x03) == 0x01)
            cf |= NS_EXT;       /* NT flag (Extension has only small capital) */
        if ((b & 0x0C) == 0x04)
            cf |= NS_BODY;      /* NT flag (Filename has only small capital) */
    }

    dj->fn[NS] = cf;            /* SFN is created */

    return FR_OK;

#else /* Non-LFN configuration */
    BYTE b, c, d, *sfn;
    int ni, si, i;
    const char *p;

    /* Create file name in directory form */
    sfn = dj->fn;
    mem_set (sfn, ' ', 11);
    si = i = b = 0;
    ni = 8;
    p = *path;
#if _FS_RPATH
    if (p[si] == '.')
    {                           /* Is this a dot entry? */
        for (;;)
        {
            c = p[si++];
            if (c != '.' || si >= 3)
                break;
            sfn[i++] = c;
        }
        if (c != '/' && c != '\\' && c > ' ')
            return FR_INVALID_NAME;
        *path = &p[si];         /* Rerurn pointer to the next segment */
        sfn[NS] = (c <= ' ') ? NS_LAST | NS_DOT : NS_DOT;   /* Set last segment flag if end of path */
        return FR_OK;
    }
#endif
    for (;;)
    {
        c = p[si++];
        if (c <= ' ' || c == '/' || c == '\\')
            break;              /* Break on end of segment */
        if (c == '.' || i >= ni)
        {
            if (ni != 8 || c != '.')
                return FR_INVALID_NAME;
            i = 8;
            ni = 11;
            b <<= 2;
            continue;
        }
        if (c >= 0x80)
        {                       /* Extended char */
#ifdef _EXCVT
            c = cvt[c - 0x80];  /* Convert extend char (SBCS) */
#else
            b |= 3;             /* Eliminate NT flag if ext char is exist */
#if !_DF1S                      /* ASCII only cfg */
            return FR_INVALID_NAME;
#endif
#endif
        }
        if (IsDBCS1 (c))
        {                       /* DBC 1st byte? */
            d = p[si++];        /* Get 2nd byte */
            if (!IsDBCS2 (d) || i >= ni - 1)    /* Reject invalid DBC */
                return FR_INVALID_NAME;
            sfn[i++] = c;
            sfn[i++] = d;
        }
        else
        {                       /* Single byte code */
            if (chk_chr (" \"*+,[=]|\x7F", c))  /* Reject illegal chrs for SFN */
                return FR_INVALID_NAME;
            if (IsUpper (c))
            {                   /* ASCII large capital? */
                b |= 2;
            }
            else
            {
                if (IsLower (c))
                {               /* ASCII small capital? */
                    b |= 1;
                    c -= 0x20;
                }
            }
            sfn[i++] = c;
        }
    }
    *path = &p[si];             /* Rerurn pointer to the next segment */
    c = (c <= ' ') ? NS_LAST : 0;   /* Set last segment flag if end of path */

    if (!i)
        return FR_INVALID_NAME; /* Reject null string */
    if (sfn[0] == 0xE5)
        sfn[0] = 0x05;          /* When first char collides with 0xE5, replace it with 0x05 */

    if (ni == 8)
        b <<= 2;
    if ((b & 0x03) == 0x01)
        c |= NS_EXT;            /* NT flag (Extension has only small capital) */
    if ((b & 0x0C) == 0x04)
        c |= NS_BODY;           /* NT flag (Filename has only small capital) */

    sfn[NS] = c;                /* Store NT flag, File name is created */

    return FR_OK;
#endif
}

/*-----------------------------------------------------------------------*/

/* Get file information from directory entry                             */

/*-----------------------------------------------------------------------*/
#if _FS_MINIMIZE <= 1
static void get_fileinfo (      /* No return code */
                             DIR * dj,  /* Pointer to the directory object */
                             FILINFO * fno  /* Pointer to the file information to be filled */
    )
{
    int i;
    BYTE c, nt, *dir;
    char *p;

    p = fno->fname;
    if (dj->sect)
    {
        dir = dj->dir;
        nt = dir[DIR_NTres];    /* NT flag */
        for (i = 0; i < 8; i++)
        {                       /* Copy name body */
            c = dir[i];
            if (c == ' ')
                break;
            if (c == 0x05)
                c = 0xE5;
            if (_USE_LFN && (nt & NS_BODY) && IsUpper (c))
                c += 0x20;
            *p++ = c;
        }
        if (dir[8] != ' ')
        {                       /* Copy name extension */
            *p++ = '.';
            for (i = 8; i < 11; i++)
            {
                c = dir[i];
                if (c == ' ')
                    break;
                if (_USE_LFN && (nt & NS_EXT) && IsUpper (c))
                    c += 0x20;
                *p++ = c;
            }
        }
        fno->fattrib = dir[DIR_Attr];   /* Attribute */
        fno->fsize = LD_DWORD (dir + DIR_FileSize); /* Size */
        fno->fdate = LD_WORD (dir + DIR_WrtDate);   /* Date */
        fno->ftime = LD_WORD (dir + DIR_WrtTime);   /* Time */
    }
    *p = 0;

#if _USE_LFN
    if (fno->lfname)
    {
        XCHAR *tp = fno->lfname;
        WCHAR w, *lfn;

        i = 0;
        if (dj->sect && dj->lfn_idx != 0xFFFF)
        {                       /* Get LFN if available */
            lfn = dj->lfn;
            while ((w = *lfn++) != 0)
            {                   /* Get an LFN char */
#if !_LFN_UNICODE
                w = ff_convert (w, 0);  /* Unicode -> OEM conversion */
                if (!w)
                {
                    i = 0;
                    break;
                }               /* Could not convert, no LFN */
                if (_DF1S && w >= 0x100)    /* Put 1st byte if it is a DBC */
                    tp[i++] = (XCHAR) (w >> 8);
#endif
                if (i >= fno->lfsize - 1)
                {
                    i = 0;
                    break;
                }               /* Buffer overrun, no LFN */
                tp[i++] = (XCHAR) w;
            }
        }
        tp[i] = 0;              /* Terminator */
    }
#endif
}
#endif /* _FS_MINIMIZE <= 1 */

/*-----------------------------------------------------------------------*/

/* Follow a file path                                                    */

/*-----------------------------------------------------------------------*/

static FRESULT follow_path (    /* FR_OK(0): successful, !=0: error code */
                               DIR * dj,    /* Directory object to return last directory and found object */
                               const XCHAR * path   /* Full-path string to find a file or directory */
    )
{
    FRESULT res;
    BYTE *dir, last;

    while (!_USE_LFN && *path == ' ')
        path++;                 /* Skip leading spaces */
#if _FS_RPATH
    if (*path == '/' || *path == '\\')
    {                           /* There is a heading separator */
        path++;
        dj->sclust = 0;         /* Strip it and start from the root dir */
    }
    else
    {                           /* No heading saparator */
        dj->sclust = dj->fs->cdir;  /* Start from the current dir */
    }
#else
    if (*path == '/' || *path == '\\')  /* Strip heading separator if exist */
        path++;
    dj->sclust = 0;             /* Start from the root dir */
#endif

    if ((UINT) * path < ' ')
    {                           /* Null path means the start directory itself */
        res = dir_seek (dj, 0);
        dj->dir = NULL;

    }
    else
    {                           /* Follow path */
        for (;;)
        {
            res = create_name (dj, &path);  /* Get a segment */
            if (res != FR_OK)
                break;
            res = dir_find (dj);    /* Find it */
            last = *(dj->fn + NS) & NS_LAST;
            if (res != FR_OK)
            {                   /* Could not find the object */
                if (res == FR_NO_FILE && !last)
                    res = FR_NO_PATH;
                break;
            }
            if (last)
                break;          /* Last segment match. Function completed. */
            dir = dj->dir;      /* There is next segment. Follow the sub directory */
            if (!(dir[DIR_Attr] & AM_DIR))
            {                   /* Cannot follow because it is a file */
                res = FR_NO_PATH;
                break;
            }
            dj->sclust =
                ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) | LD_WORD (dir +
                                                                         DIR_FstClusLO);
        }
    }

    return res;
}

/*-----------------------------------------------------------------------*/

/* Load boot record and check if it is an FAT boot record                */

/*-----------------------------------------------------------------------*/

static BYTE check_fs (          /* 0:The FAT boot record, 1:Valid boot record but not an FAT, 2:Not a boot record, 3:Error */
                         FATFS * fs,    /* File system object */
                         DWORD sect /* Sector# (lba) to check if it is an FAT boot record or not */
    )
{
    if (disk_read (fs->drive, fs->win, sect, 1) != RES_OK)  /* Load boot record */
        return 3;
    if (LD_WORD (&fs->win[BS_55AA]) != 0xAA55)  /* Check record signature (always placed at offset 510 even if the sector size is >512) */
        return 2;

    if ((LD_DWORD (&fs->win[BS_FilSysType]) & 0xFFFFFF) == 0x544146)    /* Check "FAT" string */
        return 0;
    if ((LD_DWORD (&fs->win[BS_FilSysType32]) & 0xFFFFFF) == 0x544146)
        return 0;

    return 1;
}

/*-----------------------------------------------------------------------*/

/* Make sure that the file system is valid                               */

/*-----------------------------------------------------------------------*/

FRESULT chk_mounted (           /* FR_OK(0): successful, !=0: any error occured */
                        const XCHAR ** path,    /* Pointer to pointer to the path name (drive number) */
                        FATFS ** rfs,   /* Pointer to pointer to the found file system object */
                        BYTE chk_wp /* !=0: Check media write protection for write access */
    )
{
    BYTE fmt, *tbl;
    UINT vol;
    DSTATUS stat;
    DWORD bsect, fsize, tsect, mclst;
    const XCHAR *p = *path;
    FATFS *fs;

    /* Get logical drive number from the path name */
    vol = p[0] - '0';           /* Is there a drive number? */
    if (vol <= 9 && p[1] == ':')
    {                           /* Found a drive number, get and strip it */
        p += 2;
        *path = p;              /* Return pointer to the path name */
    }
    else
    {                           /* No drive number is given */
#if _FS_RPATH
        vol = Drive;            /* Use current drive */
#else
        vol = 0;                /* Use drive 0 */
#endif
    }

    /* Check if the logical drive is valid or not */
    if (vol >= _DRIVES)         /* Is the drive number valid? */
        return FR_INVALID_DRIVE;
    *rfs = fs = FatFs[vol];     /* Returen pointer to the corresponding file system object */
    if (!fs)
        return FR_NOT_ENABLED;  /* Is the file system object available? */

    ENTER_FF (fs);              /* Lock file system */

    if (fs->fs_type)
    {                           /* If the logical drive has been mounted */
        stat = disk_status (fs->drive);
        if (!(stat & STA_NOINIT))
        {                       /* and the physical drive is kept initialized (has not been changed), */
#if !_FS_READONLY
            if (chk_wp && (stat & STA_PROTECT)) /* Check write protection if needed */
                return FR_WRITE_PROTECTED;
#endif
            return FR_OK;       /* The file system object is valid */
        }
    }

    /* The logical drive must be mounted. Following code attempts to mount the volume */

    fs->fs_type = 0;            /* Clear the file system object */
    fs->drive = (BYTE) LD2PD (vol); /* Bind the logical drive and a physical drive */
    stat = disk_initialize (fs->drive); /* Initialize low level disk I/O layer */
    if (stat & STA_NOINIT)      /* Check if the drive is ready */
        return FR_NOT_READY;
#if _MAX_SS != 512              /* Get disk sector size if needed */
    if (disk_ioctl (fs->drive, GET_SECTOR_SIZE, &SS (fs)) != RES_OK ||
        SS (fs) > _MAX_SS)
        return FR_NO_FILESYSTEM;
#endif
#if !_FS_READONLY
    if (chk_wp && (stat & STA_PROTECT)) /* Check disk write protection if needed */
        return FR_WRITE_PROTECTED;
#endif
    /* Search FAT partition on the drive */
    fmt = check_fs (fs, bsect = 0); /* Check sector 0 as an SFD format */
    if (fmt == 1)
    {                           /* Not an FAT boot record, it may be patitioned */
        /* Check a partition listed in top of the partition table */
        tbl = &fs->win[MBR_Table + LD2PT (vol) * 16];   /* Partition table */
        if (tbl[4])
        {                       /* Is the partition existing? */
            bsect = LD_DWORD (&tbl[8]); /* Partition offset in LBA */
            fmt = check_fs (fs, bsect); /* Check the partition */
        }
    }
    if (fmt == 3)
        return FR_DISK_ERR;
    if (fmt || LD_WORD (fs->win + BPB_BytsPerSec) != SS (fs))   /* No valid FAT patition is found */
        return FR_NO_FILESYSTEM;

    /* Initialize the file system object */
    fsize = LD_WORD (fs->win + BPB_FATSz16);    /* Number of sectors per FAT */
    if (!fsize)
        fsize = LD_DWORD (fs->win + BPB_FATSz32);
    fs->sects_fat = fsize;
    fs->n_fats = fs->win[BPB_NumFATs];  /* Number of FAT copies */
    fsize *= fs->n_fats;        /* (Number of sectors in FAT area) */
    fs->fatbase = bsect + LD_WORD (fs->win + BPB_RsvdSecCnt);   /* FAT start sector (lba) */
    fs->csize = fs->win[BPB_SecPerClus];    /* Number of sectors per cluster */
    fs->n_rootdir = LD_WORD (fs->win + BPB_RootEntCnt); /* Nmuber of root directory entries */
    tsect = LD_WORD (fs->win + BPB_TotSec16);   /* Number of sectors on the volume */
    if (!tsect)
        tsect = LD_DWORD (fs->win + BPB_TotSec32);
    fs->max_clust = mclst = (tsect  /* Last cluster# + 1 (Number of clusters + 2) */
                             - LD_WORD (fs->win + BPB_RsvdSecCnt) - fsize -
                             fs->n_rootdir / (SS (fs) / 32)) / fs->csize + 2;

    fmt = FS_FAT12;             /* Determine the FAT sub type */
    if (mclst >= 0xFF7)
        fmt = FS_FAT16;         /* Number of clusters >= 0xFF5 */
    if (mclst >= 0xFFF7)
        fmt = FS_FAT32;         /* Number of clusters >= 0xFFF5 */

    if (fmt == FS_FAT32)
        fs->dirbase = LD_DWORD (fs->win + BPB_RootClus);    /* Root directory start cluster */
    else
        fs->dirbase = fs->fatbase + fsize;  /* Root directory start sector (lba) */
    fs->database = fs->fatbase + fsize + fs->n_rootdir / (SS (fs) / 32);    /* Data start sector (lba) */

#if !_FS_READONLY
    /* Initialize allocation information */
    fs->free_clust = 0xFFFFFFFF;
    fs->wflag = 0;
    /* Get fsinfo if needed */
    if (fmt == FS_FAT32)
    {
        fs->fsi_flag = 0;
        fs->fsi_sector = bsect + LD_WORD (fs->win + BPB_FSInfo);
        if (disk_read (fs->drive, fs->win, fs->fsi_sector, 1) == RES_OK &&
            LD_WORD (fs->win + BS_55AA) == 0xAA55 &&
            LD_DWORD (fs->win + FSI_LeadSig) == 0x41615252 &&
            LD_DWORD (fs->win + FSI_StrucSig) == 0x61417272)
        {
            fs->last_clust = LD_DWORD (fs->win + FSI_Nxt_Free);
            fs->free_clust = LD_DWORD (fs->win + FSI_Free_Count);
        }
    }
#endif
    fs->fs_type = fmt;          /* FAT sub-type */
    fs->winsect = 0;            /* Invalidate sector cache */
#if _FS_RPATH
    fs->cdir = 0;               /* Current directory (root dir) */
#endif
    fs->id = ++Fsid;            /* File system mount ID */

    return FR_OK;
}

/*-----------------------------------------------------------------------*/

/* Check if the file/dir object is valid or not                          */

/*-----------------------------------------------------------------------*/

static FRESULT validate (       /* FR_OK(0): The object is valid, !=0: Invalid */
                            FATFS * fs, /* Pointer to the file system object */
                            WORD id /* Member id of the target object to be checked */
    )
{
    if (!fs || !fs->fs_type || fs->id != id)
        return FR_INVALID_OBJECT;

    ENTER_FF (fs);              /* Lock file system */

    if (disk_status (fs->drive) & STA_NOINIT)
        return FR_NOT_READY;

    return FR_OK;
}

/*--------------------------------------------------------------------------

   Public Functions

--------------------------------------------------------------------------*/

/*-----------------------------------------------------------------------*/

/* Mount/Unmount a Locical Drive                                         */

/*-----------------------------------------------------------------------*/

FRESULT f_mount (BYTE vol,      /* Logical drive number to be mounted/unmounted */
                 FATFS * fs     /* Pointer to new file system object (NULL for unmount) */
    )
{
    FATFS *rfs;

    if (vol >= _DRIVES)         /* Check if the drive number is valid */
        return FR_INVALID_DRIVE;
    rfs = FatFs[vol];           /* Get current fs object */

    if (rfs)
    {
#if _FS_REENTRANT               /* Discard sync object of the current volume */
        if (!ff_del_syncobj (rfs->sobj))
            return FR_INT_ERR;
#endif
        rfs->fs_type = 0;       /* Clear old fs object */
    }

    if (fs)
    {
        fs->fs_type = 0;        /* Clear new fs object */
#if _FS_REENTRANT               /* Create sync object for the new volume */
        if (!ff_cre_syncobj (vol, &fs->sobj))
            return FR_INT_ERR;
#endif
    }
    FatFs[vol] = fs;            /* Register new fs object */

    return FR_OK;
}

/*-----------------------------------------------------------------------*/

/* Open or Create a File                                                 */

/*-----------------------------------------------------------------------*/

FRESULT f_open (FIL * fp,       /* Pointer to the blank file object */
                const XCHAR * path, /* Pointer to the file name */
                BYTE mode       /* Access mode and file open mode flags */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);
    BYTE *dir;

    fp->fs = NULL;              /* Clear file object */
#if !_FS_READONLY
    mode &=
        (FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS |
         FA_CREATE_NEW);
    res =
        chk_mounted (&path, &dj.fs,
                     (BYTE) (mode &
                             (FA_WRITE | FA_CREATE_ALWAYS | FA_OPEN_ALWAYS |
                              FA_CREATE_NEW)));
#else
    mode &= FA_READ;
    res = chk_mounted (&path, &dj.fs, 0);
#endif
    if (res != FR_OK)
        LEAVE_FF (dj.fs, res);
    INITBUF (dj, sfn, lfn);
    res = follow_path (&dj, path);  /* Follow the file path */

#if !_FS_READONLY
    /* Create or Open a file */
    if (mode & (FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW))
    {
        DWORD ps, cl;

        if (res != FR_OK)
        {                       /* No file, create new */
            if (res == FR_NO_FILE)  /* There is no file to open, create a new entry */
                res = dir_register (&dj);
            if (res != FR_OK)
                LEAVE_FF (dj.fs, res);
            mode |= FA_CREATE_ALWAYS;
            dir = dj.dir;       /* Created entry (SFN entry) */
        }
        else
        {                       /* Any object is already existing */
            if (mode & FA_CREATE_NEW)   /* Cannot create new */
                LEAVE_FF (dj.fs, FR_EXIST);
            dir = dj.dir;
            if (!dir || (dir[DIR_Attr] & (AM_RDO | AM_DIR)))    /* Cannot overwrite it (R/O or DIR) */
                LEAVE_FF (dj.fs, FR_DENIED);
            if (mode & FA_CREATE_ALWAYS)
            {                   /* Resize it to zero on over write mode */
                cl = ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) | LD_WORD (dir + DIR_FstClusLO); /* Get start cluster */
                ST_WORD (dir + DIR_FstClusHI, 0);   /* cluster = 0 */
                ST_WORD (dir + DIR_FstClusLO, 0);
                ST_DWORD (dir + DIR_FileSize, 0);   /* size = 0 */
                dj.fs->wflag = 1;
                ps = dj.fs->winsect;    /* Remove the cluster chain */
                if (cl)
                {
                    res = remove_chain (dj.fs, cl);
                    if (res)
                        LEAVE_FF (dj.fs, res);
                    dj.fs->last_clust = cl - 1; /* Reuse the cluster hole */
                }
                res = move_window (dj.fs, ps);
                if (res != FR_OK)
                    LEAVE_FF (dj.fs, res);
            }
        }
        if (mode & FA_CREATE_ALWAYS)
        {
            dir[DIR_Attr] = 0;  /* Reset attribute */
            ps = get_fattime ();
            ST_DWORD (dir + DIR_CrtTime, ps);   /* Created time */
            dj.fs->wflag = 1;
            mode |= FA__WRITTEN;    /* Set file changed flag */
        }
    }
    /* Open an existing file */
    else
    {
#endif /* !_FS_READONLY */
        if (res != FR_OK)
            LEAVE_FF (dj.fs, res);  /* Follow failed */
        dir = dj.dir;
        if (!dir || (dir[DIR_Attr] & AM_DIR))   /* It is a directory */
            LEAVE_FF (dj.fs, FR_NO_FILE);
#if !_FS_READONLY
        if ((mode & FA_WRITE) && (dir[DIR_Attr] & AM_RDO))  /* R/O violation */
            LEAVE_FF (dj.fs, FR_DENIED);
    }
    fp->dir_sect = dj.fs->winsect;  /* Pointer to the directory entry */
    fp->dir_ptr = dj.dir;
#endif
    fp->flag = mode;            /* File access mode */
    fp->org_clust =             /* File start cluster */
        ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) | LD_WORD (dir +
                                                                 DIR_FstClusLO);
    fp->fsize = LD_DWORD (dir + DIR_FileSize);  /* File size */
    fp->fptr = 0;
    fp->csect = 255;            /* File pointer */
    fp->dsect = 0;
    fp->fs = dj.fs;
    fp->id = dj.fs->id;         /* Owner file system object of the file */

    LEAVE_FF (dj.fs, FR_OK);
}

/*-----------------------------------------------------------------------*/

/* Read File                                                             */

/*-----------------------------------------------------------------------*/

FRESULT f_read (FIL * fp,       /* Pointer to the file object */
                void *buff,     /* Pointer to data buffer */
                UINT btr,       /* Number of bytes to read */
                UINT * br       /* Pointer to number of bytes read */
    )
{
    FRESULT res;
    DWORD clst, sect, remain;
    UINT rcnt, cc;
    BYTE *rbuff = buff;

    *br = 0;                    /* Initialize bytes read */

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res != FR_OK)
        LEAVE_FF (fp->fs, res);
    if (fp->flag & FA__ERROR)   /* Check abort flag */
        LEAVE_FF (fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_READ))  /* Check access mode */
        LEAVE_FF (fp->fs, FR_DENIED);
    remain = fp->fsize - fp->fptr;
    if (btr > remain)
        btr = (UINT) remain;    /* Truncate btr by remaining bytes */

    for (; btr;                 /* Repeat until all data transferred */
         rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt)
    {
        if ((fp->fptr % SS (fp->fs)) == 0)
        {                       /* On the sector boundary? */
            if (fp->csect >= fp->fs->csize)
            {                   /* On the cluster boundary? */
                clst = (fp->fptr == 0) ?    /* On the top of the file? */
                    fp->org_clust : get_fat (fp->fs, fp->curr_clust);
                if (clst <= 1)
                    ABORT (fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;  /* Update current cluster */
                fp->csect = 0;  /* Reset sector offset in the cluster */
            }
            sect = clust2sect (fp->fs, fp->curr_clust); /* Get current sector */
            if (!sect)
                ABORT (fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btr / SS (fp->fs); /* When remaining bytes >= sector size, */
            if (cc)
            {                   /* Read maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_read (fp->fs->drive, rbuff, sect, (BYTE) cc) != RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
#if !_FS_READONLY && _FS_MINIMIZE <= 2
#if _FS_TINY
                if (fp->fs->wflag && fp->fs->winsect - sect < cc)   /* Replace one of the read sectors with cached data if it contains a dirty sector */
                    mem_cpy (rbuff + ((fp->fs->winsect - sect) * SS (fp->fs)),
                             fp->fs->win, SS (fp->fs));
#else
                if ((fp->flag & FA__DIRTY) && fp->dsect - sect < cc)    /* Replace one of the read sectors with cached data if it contains a dirty sector */
                    mem_cpy (rbuff + ((fp->dsect - sect) * SS (fp->fs)),
                             fp->buf, SS (fp->fs));
#endif
#endif
                fp->csect += (BYTE) cc; /* Next sector address in the cluster */
                rcnt = SS (fp->fs) * cc;    /* Number of bytes transferred */
                continue;
            }
#if !_FS_TINY
#if !_FS_READONLY
            if (fp->flag & FA__DIRTY)
            {                   /* Write sector I/O buffer if needed */
                if (disk_write (fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            if (fp->dsect != sect)
            {                   /* Fill sector buffer with file data */
                if (disk_read (fp->fs->drive, fp->buf, sect, 1) != RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
            }
#endif
            fp->dsect = sect;
            fp->csect++;        /* Next sector address in the cluster */
        }
        rcnt = SS (fp->fs) - (fp->fptr % SS (fp->fs));  /* Get partial sector data from sector buffer */
        if (rcnt > btr)
            rcnt = btr;
#if _FS_TINY
        if (move_window (fp->fs, fp->dsect))    /* Move sector window */
            ABORT (fp->fs, FR_DISK_ERR);
        mem_cpy (rbuff, &fp->fs->win[fp->fptr % SS (fp->fs)], rcnt);    /* Pick partial sector */
#else
        mem_cpy (rbuff, &fp->buf[fp->fptr % SS (fp->fs)], rcnt);    /* Pick partial sector */
#endif
    }

    LEAVE_FF (fp->fs, FR_OK);
}

#if !_FS_READONLY

/*-----------------------------------------------------------------------*/

/* Write File                                                            */

/*-----------------------------------------------------------------------*/

FRESULT f_write (FIL * fp,      /* Pointer to the file object */
                 const void *buff,  /* Pointer to the data to be written */
                 UINT btw,      /* Number of bytes to write */
                 UINT * bw      /* Pointer to number of bytes written */
    )
{
    FRESULT res;
    DWORD clst, sect;
    UINT wcnt, cc;
    const BYTE *wbuff = buff;

    *bw = 0;                    /* Initialize bytes written */

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res != FR_OK)
        LEAVE_FF (fp->fs, res);
    if (fp->flag & FA__ERROR)   /* Check abort flag */
        LEAVE_FF (fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_WRITE)) /* Check access mode */
        LEAVE_FF (fp->fs, FR_DENIED);
    if (fp->fsize + btw < fp->fsize)
        btw = 0;                /* File size cannot reach 4GB */

    for (; btw;                 /* Repeat until all data transferred */
         wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt)
    {
        if ((fp->fptr % SS (fp->fs)) == 0)
        {                       /* On the sector boundary? */
            if (fp->csect >= fp->fs->csize)
            {                   /* On the cluster boundary? */
                if (fp->fptr == 0)
                {               /* On the top of the file? */
                    clst = fp->org_clust;   /* Follow from the origin */
                    if (clst == 0)  /* When there is no cluster chain, */
                        fp->org_clust = clst = create_chain (fp->fs, 0);    /* Create a new cluster chain */
                }
                else
                {               /* Middle or end of the file */
                    clst = create_chain (fp->fs, fp->curr_clust);   /* Follow or streach cluster chain */
                }
                if (clst == 0)
                    break;      /* Could not allocate a new cluster (disk full) */
                if (clst == 1)
                    ABORT (fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;  /* Update current cluster */
                fp->csect = 0;  /* Reset sector address in the cluster */
            }
#if _FS_TINY
            if (fp->fs->winsect == fp->dsect && move_window (fp->fs, 0))    /* Write back data buffer prior to following direct transfer */
                ABORT (fp->fs, FR_DISK_ERR);
#else
            if (fp->flag & FA__DIRTY)
            {                   /* Write back data buffer prior to following direct transfer */
                if (disk_write (fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            sect = clust2sect (fp->fs, fp->curr_clust); /* Get current sector */
            if (!sect)
                ABORT (fp->fs, FR_INT_ERR);
            sect += fp->csect;
            cc = btw / SS (fp->fs); /* When remaining bytes >= sector size, */
            if (cc)
            {                   /* Write maximum contiguous sectors directly */
                if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
                    cc = fp->fs->csize - fp->csect;
                if (disk_write (fp->fs->drive, wbuff, sect, (BYTE) cc) !=
                    RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
#if _FS_TINY
                if (fp->fs->winsect - sect < cc)
                {               /* Refill sector cache if it gets dirty by the direct write */
                    mem_cpy (fp->fs->win,
                             wbuff + ((fp->fs->winsect - sect) * SS (fp->fs)),
                             SS (fp->fs));
                    fp->fs->wflag = 0;
                }
#else
                if (fp->dsect - sect < cc)
                {               /* Refill sector cache if it gets dirty by the direct write */
                    mem_cpy (fp->buf,
                             wbuff + ((fp->dsect - sect) * SS (fp->fs)),
                             SS (fp->fs));
                    fp->flag &= ~FA__DIRTY;
                }
#endif
                fp->csect += (BYTE) cc; /* Next sector address in the cluster */
                wcnt = SS (fp->fs) * cc;    /* Number of bytes transferred */
                continue;
            }
#if _FS_TINY
            if (fp->fptr >= fp->fsize)
            {                   /* Avoid silly buffer filling at growing edge */
                if (move_window (fp->fs, 0))
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->fs->winsect = sect;
            }
#else
            if (fp->dsect != sect)
            {                   /* Fill sector buffer with file data */
                if (fp->fptr < fp->fsize &&
                    disk_read (fp->fs->drive, fp->buf, sect, 1) != RES_OK)
                    ABORT (fp->fs, FR_DISK_ERR);
            }
#endif
            fp->dsect = sect;
            fp->csect++;        /* Next sector address in the cluster */
        }
        wcnt = SS (fp->fs) - (fp->fptr % SS (fp->fs));  /* Put partial sector into file I/O buffer */
        if (wcnt > btw)
            wcnt = btw;
#if _FS_TINY
        if (move_window (fp->fs, fp->dsect))    /* Move sector window */
            ABORT (fp->fs, FR_DISK_ERR);
        mem_cpy (&fp->fs->win[fp->fptr % SS (fp->fs)], wbuff, wcnt);    /* Fit partial sector */
        fp->fs->wflag = 1;
#else
        mem_cpy (&fp->buf[fp->fptr % SS (fp->fs)], wbuff, wcnt);    /* Fit partial sector */
        fp->flag |= FA__DIRTY;
#endif
    }

    if (fp->fptr > fp->fsize)
        fp->fsize = fp->fptr;   /* Update file size if needed */
    fp->flag |= FA__WRITTEN;    /* Set file changed flag */

    LEAVE_FF (fp->fs, FR_OK);
}

/*-----------------------------------------------------------------------*/

/* Synchronize the File Object                                           */

/*-----------------------------------------------------------------------*/

FRESULT f_sync (FIL * fp        /* Pointer to the file object */
    )
{
    FRESULT res;
    DWORD tim;
    BYTE *dir;

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res == FR_OK)
    {
        if (fp->flag & FA__WRITTEN)
        {                       /* Has the file been written? */
#if !_FS_TINY                   /* Write-back dirty buffer */
            if (fp->flag & FA__DIRTY)
            {
                if (disk_write (fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                    LEAVE_FF (fp->fs, FR_DISK_ERR);
                fp->flag &= ~FA__DIRTY;
            }
#endif
            /* Update the directory entry */
            res = move_window (fp->fs, fp->dir_sect);
            if (res == FR_OK)
            {
                dir = fp->dir_ptr;
                dir[DIR_Attr] |= AM_ARC;    /* Set archive bit */
                ST_DWORD (dir + DIR_FileSize, fp->fsize);   /* Update file size */
                ST_WORD (dir + DIR_FstClusLO, fp->org_clust);   /* Update start cluster */
                ST_WORD (dir + DIR_FstClusHI, fp->org_clust >> 16);
                tim = get_fattime ();   /* Updated time */
                ST_DWORD (dir + DIR_WrtTime, tim);
                fp->flag &= ~FA__WRITTEN;
                fp->fs->wflag = 1;
                res = sync (fp->fs);
            }
        }
    }

    LEAVE_FF (fp->fs, res);
}

#endif /* !_FS_READONLY */

/*-----------------------------------------------------------------------*/

/* Close File                                                            */

/*-----------------------------------------------------------------------*/

FRESULT f_close (FIL * fp       /* Pointer to the file object to be closed */
    )
{
    FRESULT res;

#if _FS_READONLY
    res = validate (fp->fs, fp->id);
    if (res == FR_OK)
        fp->fs = NULL;
    LEAVE_FF (fp->fs, res);
#else
    res = f_sync (fp);
    if (res == FR_OK)
        fp->fs = NULL;
    return res;
#endif
}

/*-----------------------------------------------------------------------*/

/* Change Current Drive/Directory                                        */

/*-----------------------------------------------------------------------*/

#if _FS_RPATH

FRESULT f_chdrive (BYTE drv     /* Drive number */
    )
{
    if (drv >= _DRIVES)
        return FR_INVALID_DRIVE;

    Drive = drv;

    return FR_OK;
}

FRESULT f_chdir (const XCHAR * path /* Pointer to the directory path */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);
    BYTE *dir;

    res = chk_mounted (&path, &dj.fs, 0);
    if (res == FR_OK)
    {
        INITBUF (dj, sfn, lfn);
        res = follow_path (&dj, path);  /* Follow the file path */
        if (res == FR_OK)
        {                       /* Follow completed */
            dir = dj.dir;       /* Pointer to the entry */
            if (!dir)
            {
                dj.fs->cdir = 0;    /* No entry (root dir) */
            }
            else
            {
                if (dir[DIR_Attr] & AM_DIR) /* Reached to the dir */
                    dj.fs->cdir =
                        ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) |
                        LD_WORD (dir + DIR_FstClusLO);
                else
                    res = FR_NO_PATH;   /* Could not reach the dir (it is a file) */
            }
        }
        if (res == FR_NO_FILE)
            res = FR_NO_PATH;
    }

    LEAVE_FF (dj.fs, res);
}

#endif

#if _FS_MINIMIZE <= 2

/*-----------------------------------------------------------------------*/

/* Seek File R/W Pointer                                                 */

/*-----------------------------------------------------------------------*/

FRESULT f_lseek (FIL * fp,      /* Pointer to the file object */
                 DWORD ofs      /* File pointer from top of file */
    )
{
    FRESULT res;
    DWORD clst, bcs, nsect, ifptr;

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res != FR_OK)
        LEAVE_FF (fp->fs, res);
    if (fp->flag & FA__ERROR)   /* Check abort flag */
        LEAVE_FF (fp->fs, FR_INT_ERR);
    if (ofs > fp->fsize         /* In read-only mode, clip offset with the file size */
#if !_FS_READONLY
        && !(fp->flag & FA_WRITE)
#endif
        )
        ofs = fp->fsize;

    ifptr = fp->fptr;
    fp->fptr = nsect = 0;
    fp->csect = 255;
    if (ofs > 0)
    {
        bcs = (DWORD) fp->fs->csize * SS (fp->fs);  /* Cluster size (byte) */
        if (ifptr > 0 && (ofs - 1) / bcs >= (ifptr - 1) / bcs)
        {                       /* When seek to same or following cluster, */
            fp->fptr = (ifptr - 1) & ~(bcs - 1);    /* start from the current cluster */
            ofs -= fp->fptr;
            clst = fp->curr_clust;
        }
        else
        {                       /* When seek to back cluster, */
            clst = fp->org_clust;   /* start from the first cluster */
#if !_FS_READONLY
            if (clst == 0)
            {                   /* If no cluster chain, create a new chain */
                clst = create_chain (fp->fs, 0);
                if (clst == 1)
                    ABORT (fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->org_clust = clst;
            }
#endif
            fp->curr_clust = clst;
        }
        if (clst != 0)
        {
            while (ofs > bcs)
            {                   /* Cluster following loop */
#if !_FS_READONLY
                if (fp->flag & FA_WRITE)
                {               /* Check if in write mode or not */
                    clst = create_chain (fp->fs, clst); /* Force streached if in write mode */
                    if (clst == 0)
                    {           /* When disk gets full, clip file size */
                        ofs = bcs;
                        break;
                    }
                }
                else
#endif
                    clst = get_fat (fp->fs, clst);  /* Follow cluster chain if not in write mode */
                if (clst == 0xFFFFFFFF)
                    ABORT (fp->fs, FR_DISK_ERR);
                if (clst <= 1 || clst >= fp->fs->max_clust)
                    ABORT (fp->fs, FR_INT_ERR);
                fp->curr_clust = clst;
                fp->fptr += bcs;
                ofs -= bcs;
            }
            fp->fptr += ofs;
            fp->csect = (BYTE) (ofs / SS (fp->fs)); /* Sector offset in the cluster */
            if (ofs % SS (fp->fs))
            {
                nsect = clust2sect (fp->fs, clst);  /* Current sector */
                if (!nsect)
                    ABORT (fp->fs, FR_INT_ERR);
                nsect += fp->csect;
                fp->csect++;
            }
        }
    }
    if (fp->fptr % SS (fp->fs) && nsect != fp->dsect)
    {
#if !_FS_TINY
#if !_FS_READONLY
        if (fp->flag & FA__DIRTY)
        {                       /* Write-back dirty buffer if needed */
            if (disk_write (fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
                ABORT (fp->fs, FR_DISK_ERR);
            fp->flag &= ~FA__DIRTY;
        }
#endif
        if (disk_read (fp->fs->drive, fp->buf, nsect, 1) != RES_OK)
            ABORT (fp->fs, FR_DISK_ERR);
#endif
        fp->dsect = nsect;
    }
#if !_FS_READONLY
    if (fp->fptr > fp->fsize)
    {                           /* Set changed flag if the file size is extended */
        fp->fsize = fp->fptr;
        fp->flag |= FA__WRITTEN;
    }
#endif

    LEAVE_FF (fp->fs, res);
}

#if _FS_MINIMIZE <= 1

/*-----------------------------------------------------------------------*/

/* Create a Directroy Object                                             */

/*-----------------------------------------------------------------------*/

FRESULT f_opendir (DIR * dj,    /* Pointer to directory object to create */
                   const XCHAR * path   /* Pointer to the directory path */
    )
{
    FRESULT res;

    NAMEBUF (sfn, lfn);
    BYTE *dir;

    res = chk_mounted (&path, &dj->fs, 0);
    if (res == FR_OK)
    {
        INITBUF ((*dj), sfn, lfn);
        res = follow_path (dj, path);   /* Follow the path to the directory */
        if (res == FR_OK)
        {                       /* Follow completed */
            dir = dj->dir;
            if (dir)
            {                   /* It is not the root dir */
                if (dir[DIR_Attr] & AM_DIR)
                {               /* The object is a directory */
                    dj->sclust =
                        ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) |
                        LD_WORD (dir + DIR_FstClusLO);
                }
                else
                {               /* The object is not a directory */
                    res = FR_NO_PATH;
                }
            }
            if (res == FR_OK)
            {
                dj->id = dj->fs->id;
                res = dir_seek (dj, 0); /* Rewind dir */
            }
        }
        if (res == FR_NO_FILE)
            res = FR_NO_PATH;
    }

    LEAVE_FF (dj->fs, res);
}

/*-----------------------------------------------------------------------*/

/* Read Directory Entry in Sequense                                      */

/*-----------------------------------------------------------------------*/

FRESULT f_readdir (DIR * dj,    /* Pointer to the open directory object */
                   FILINFO * fno    /* Pointer to file information to return */
    )
{
    FRESULT res;

    NAMEBUF (sfn, lfn);

    res = validate (dj->fs, dj->id);    /* Check validity of the object */
    if (res == FR_OK)
    {
        INITBUF ((*dj), sfn, lfn);
        if (!fno)
        {
            res = dir_seek (dj, 0);
        }
        else
        {
            res = dir_read (dj);
            if (res == FR_NO_FILE)
            {
                dj->sect = 0;
                res = FR_OK;
            }
            if (res == FR_OK)
            {                   /* A valid entry is found */
                get_fileinfo (dj, fno); /* Get the object information */
                res = dir_next (dj, FALSE); /* Increment index for next */
                if (res == FR_NO_FILE)
                {
                    dj->sect = 0;
                    res = FR_OK;
                }
            }
        }
    }

    LEAVE_FF (dj->fs, res);
}

#if _FS_MINIMIZE == 0

/*-----------------------------------------------------------------------*/

/* Get File Status                                                       */

/*-----------------------------------------------------------------------*/

FRESULT f_stat (const XCHAR * path, /* Pointer to the file path */
                FILINFO * fno   /* Pointer to file information to return */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);

    res = chk_mounted (&path, &dj.fs, 0);
    if (res == FR_OK)
    {
        INITBUF (dj, sfn, lfn);
        res = follow_path (&dj, path);  /* Follow the file path */
        if (res == FR_OK)
        {                       /* Follwo completed */
            if (dj.dir)         /* Found an object */
                get_fileinfo (&dj, fno);
            else                /* It is root dir */
                res = FR_INVALID_NAME;
        }
    }

    LEAVE_FF (dj.fs, res);
}

#if !_FS_READONLY

/*-----------------------------------------------------------------------*/

/* Get Number of Free Clusters                                           */

/*-----------------------------------------------------------------------*/

FRESULT f_getfree (const XCHAR * path,  /* Pointer to the logical drive number (root dir) */
                   DWORD * nclst,   /* Pointer to the variable to return number of free clusters */
                   FATFS ** fatfs   /* Pointer to pointer to corresponding file system object to return */
    )
{
    FRESULT res;
    DWORD n, clst, sect, stat;
    UINT i;
    BYTE fat, *p;

    /* Get drive number */
    res = chk_mounted (&path, fatfs, 0);
    if (res != FR_OK)
        LEAVE_FF (*fatfs, res);

    /* If number of free cluster is valid, return it without cluster scan. */
    if ((*fatfs)->free_clust <= (*fatfs)->max_clust - 2)
    {
        *nclst = (*fatfs)->free_clust;
        LEAVE_FF (*fatfs, FR_OK);
    }

    /* Get number of free clusters */
    fat = (*fatfs)->fs_type;
    n = 0;
    if (fat == FS_FAT12)
    {
        clst = 2;
        do
        {
            stat = get_fat (*fatfs, clst);
            if (stat == 0xFFFFFFFF)
                LEAVE_FF (*fatfs, FR_DISK_ERR);
            if (stat == 1)
                LEAVE_FF (*fatfs, FR_INT_ERR);
            if (stat == 0)
                n++;
        } while (++clst < (*fatfs)->max_clust);
    }
    else
    {
        clst = (*fatfs)->max_clust;
        sect = (*fatfs)->fatbase;
        i = 0;
        p = 0;
        do
        {
            if (!i)
            {
                res = move_window (*fatfs, sect++);
                if (res != FR_OK)
                    LEAVE_FF (*fatfs, res);
                p = (*fatfs)->win;
                i = SS (*fatfs);
            }
            if (fat == FS_FAT16)
            {
                if (LD_WORD (p) == 0)
                    n++;
                p += 2;
                i -= 2;
            }
            else
            {
                if ((LD_DWORD (p) & 0x0FFFFFFF) == 0)
                    n++;
                p += 4;
                i -= 4;
            }
        } while (--clst);
    }
    (*fatfs)->free_clust = n;
    if (fat == FS_FAT32)
        (*fatfs)->fsi_flag = 1;
    *nclst = n;

    LEAVE_FF (*fatfs, FR_OK);
}

/*-----------------------------------------------------------------------*/

/* Truncate File                                                         */

/*-----------------------------------------------------------------------*/

FRESULT f_truncate (FIL * fp    /* Pointer to the file object */
    )
{
    FRESULT res;
    DWORD ncl;

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res != FR_OK)
        LEAVE_FF (fp->fs, res);
    if (fp->flag & FA__ERROR)   /* Check abort flag */
        LEAVE_FF (fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_WRITE)) /* Check access mode */
        LEAVE_FF (fp->fs, FR_DENIED);

    if (fp->fsize > fp->fptr)
    {
        fp->fsize = fp->fptr;   /* Set file size to current R/W point */
        fp->flag |= FA__WRITTEN;
        if (fp->fptr == 0)
        {                       /* When set file size to zero, remove entire cluster chain */
            res = remove_chain (fp->fs, fp->org_clust);
            fp->org_clust = 0;
        }
        else
        {                       /* When truncate a part of the file, remove remaining clusters */
            ncl = get_fat (fp->fs, fp->curr_clust);
            res = FR_OK;
            if (ncl == 0xFFFFFFFF)
                res = FR_DISK_ERR;
            if (ncl == 1)
                res = FR_INT_ERR;
            if (res == FR_OK && ncl < fp->fs->max_clust)
            {
                res = put_fat (fp->fs, fp->curr_clust, 0x0FFFFFFF);
                if (res == FR_OK)
                    res = remove_chain (fp->fs, ncl);
            }
        }
    }
    if (res != FR_OK)
        fp->flag |= FA__ERROR;

    LEAVE_FF (fp->fs, res);
}

/*-----------------------------------------------------------------------*/

/* Delete a File or Directory                                            */

/*-----------------------------------------------------------------------*/

FRESULT f_unlink (const XCHAR * path    /* Pointer to the file or directory path */
    )
{
    FRESULT res;
    DIR dj, sdj;

    NAMEBUF (sfn, lfn);
    BYTE *dir;
    DWORD dclst;

    res = chk_mounted (&path, &dj.fs, 1);
    if (res != FR_OK)
        LEAVE_FF (dj.fs, res);

    INITBUF (dj, sfn, lfn);
    res = follow_path (&dj, path);  /* Follow the file path */
    if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
        res = FR_INVALID_NAME;
    if (res != FR_OK)
        LEAVE_FF (dj.fs, res);  /* Follow failed */

    dir = dj.dir;
    if (!dir)                   /* Is it the root directory? */
        LEAVE_FF (dj.fs, FR_INVALID_NAME);
    if (dir[DIR_Attr] & AM_RDO) /* Is it a R/O object? */
        LEAVE_FF (dj.fs, FR_DENIED);
    dclst =
        ((DWORD) LD_WORD (dir + DIR_FstClusHI) << 16) | LD_WORD (dir +
                                                                 DIR_FstClusLO);

    if (dir[DIR_Attr] & AM_DIR)
    {                           /* It is a sub-directory */
        if (dclst < 2)
            LEAVE_FF (dj.fs, FR_INT_ERR);
        mem_cpy (&sdj, &dj, sizeof (DIR));  /* Check if the sub-dir is empty or not */
        sdj.sclust = dclst;
        res = dir_seek (&sdj, 2);
        if (res != FR_OK)
            LEAVE_FF (dj.fs, res);
        res = dir_read (&sdj);
        if (res == FR_OK)
            res = FR_DENIED;    /* Not empty sub-dir */
        if (res != FR_NO_FILE)
            LEAVE_FF (dj.fs, res);
    }

    res = dir_remove (&dj);     /* Remove directory entry */
    if (res == FR_OK)
    {
        if (dclst)
            res = remove_chain (dj.fs, dclst);  /* Remove the cluster chain */
        if (res == FR_OK)
            res = sync (dj.fs);
    }

    LEAVE_FF (dj.fs, res);
}

/*-----------------------------------------------------------------------*/

/* Create a Directory                                                    */

/*-----------------------------------------------------------------------*/

FRESULT f_mkdir (const XCHAR * path /* Pointer to the directory path */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);
    BYTE *dir, n;
    DWORD dsect, dclst, pclst, tim;

    res = chk_mounted (&path, &dj.fs, 1);
    if (res != FR_OK)
        LEAVE_FF (dj.fs, res);

    INITBUF (dj, sfn, lfn);
    res = follow_path (&dj, path);  /* Follow the file path */
    if (res == FR_OK)
        res = FR_EXIST;         /* Any file or directory is already existing */
    if (_FS_RPATH && res == FR_NO_FILE && (dj.fn[NS] & NS_DOT))
        res = FR_INVALID_NAME;
    if (res != FR_NO_FILE)      /* Any error occured */
        LEAVE_FF (dj.fs, res);

    dclst = create_chain (dj.fs, 0);    /* Allocate a new cluster for new directory table */
    res = FR_OK;
    if (dclst == 0)
        res = FR_DENIED;
    if (dclst == 1)
        res = FR_INT_ERR;
    if (dclst == 0xFFFFFFFF)
        res = FR_DISK_ERR;
    if (res == FR_OK)
        res = move_window (dj.fs, 0);
    if (res != FR_OK)
        LEAVE_FF (dj.fs, res);
    dsect = clust2sect (dj.fs, dclst);

    dir = dj.fs->win;           /* Initialize the new directory table */
    mem_set (dir, 0, SS (dj.fs));
    mem_set (dir + DIR_Name, ' ', 8 + 3);   /* Create "." entry */
    dir[DIR_Name] = '.';
    dir[DIR_Attr] = AM_DIR;
    tim = get_fattime ();
    ST_DWORD (dir + DIR_WrtTime, tim);
    ST_WORD (dir + DIR_FstClusLO, dclst);
    ST_WORD (dir + DIR_FstClusHI, dclst >> 16);
    mem_cpy (dir + 32, dir, 32);    /* Create ".." entry */
    dir[33] = '.';
    pclst = dj.sclust;
    if (dj.fs->fs_type == FS_FAT32 && pclst == dj.fs->dirbase)
        pclst = 0;
    ST_WORD (dir + 32 + DIR_FstClusLO, pclst);
    ST_WORD (dir + 32 + DIR_FstClusHI, pclst >> 16);
    for (n = 0; n < dj.fs->csize; n++)
    {                           /* Write dot entries and clear left sectors */
        dj.fs->winsect = dsect++;
        dj.fs->wflag = 1;
        res = move_window (dj.fs, 0);
        if (res)
            LEAVE_FF (dj.fs, res);
        mem_set (dir, 0, SS (dj.fs));
    }

    res = dir_register (&dj);
    if (res != FR_OK)
    {
        remove_chain (dj.fs, dclst);
    }
    else
    {
        dir = dj.dir;
        dir[DIR_Attr] = AM_DIR; /* Attribute */
        ST_DWORD (dir + DIR_WrtTime, tim);  /* Crated time */
        ST_WORD (dir + DIR_FstClusLO, dclst);   /* Table start cluster */
        ST_WORD (dir + DIR_FstClusHI, dclst >> 16);
        dj.fs->wflag = 1;
        res = sync (dj.fs);
    }

    LEAVE_FF (dj.fs, res);
}

/*-----------------------------------------------------------------------*/

/* Change File Attribute                                                 */

/*-----------------------------------------------------------------------*/

FRESULT f_chmod (const XCHAR * path,    /* Pointer to the file path */
                 BYTE value,    /* Attribute bits */
                 BYTE mask      /* Attribute mask to change */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);
    BYTE *dir;

    res = chk_mounted (&path, &dj.fs, 1);
    if (res == FR_OK)
    {
        INITBUF (dj, sfn, lfn);
        res = follow_path (&dj, path);  /* Follow the file path */
        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
            res = FR_INVALID_NAME;
        if (res == FR_OK)
        {
            dir = dj.dir;
            if (!dir)
            {                   /* Is it a root directory? */
                res = FR_INVALID_NAME;
            }
            else
            {                   /* File or sub directory */
                mask &= AM_RDO | AM_HID | AM_SYS | AM_ARC;  /* Valid attribute mask */
                dir[DIR_Attr] = (value & mask) | (dir[DIR_Attr] & (BYTE) ~ mask);   /* Apply attribute change */
                dj.fs->wflag = 1;
                res = sync (dj.fs);
            }
        }
    }

    LEAVE_FF (dj.fs, res);
}

/*-----------------------------------------------------------------------*/

/* Change Timestamp                                                      */

/*-----------------------------------------------------------------------*/

FRESULT f_utime (const XCHAR * path,    /* Pointer to the file/directory name */
                 const FILINFO * fno    /* Pointer to the timestamp to be set */
    )
{
    FRESULT res;
    DIR dj;

    NAMEBUF (sfn, lfn);
    BYTE *dir;

    res = chk_mounted (&path, &dj.fs, 1);
    if (res == FR_OK)
    {
        INITBUF (dj, sfn, lfn);
        res = follow_path (&dj, path);  /* Follow the file path */
        if (_FS_RPATH && res == FR_OK && (dj.fn[NS] & NS_DOT))
            res = FR_INVALID_NAME;
        if (res == FR_OK)
        {
            dir = dj.dir;
            if (!dir)
            {                   /* Root directory */
                res = FR_INVALID_NAME;
            }
            else
            {                   /* File or sub-directory */
                ST_WORD (dir + DIR_WrtTime, fno->ftime);
                ST_WORD (dir + DIR_WrtDate, fno->fdate);
                dj.fs->wflag = 1;
                res = sync (dj.fs);
            }
        }
    }

    LEAVE_FF (dj.fs, res);
}

/*-----------------------------------------------------------------------*/

/* Rename File/Directory                                                 */

/*-----------------------------------------------------------------------*/

FRESULT f_rename (const XCHAR * path_old,   /* Pointer to the old name */
                  const XCHAR * path_new    /* Pointer to the new name */
    )
{
    FRESULT res;
    DIR dj_old, dj_new;

    NAMEBUF (sfn, lfn);
    BYTE buf[21], *dir;
    DWORD dw;

    INITBUF (dj_old, sfn, lfn);
    res = chk_mounted (&path_old, &dj_old.fs, 1);
    if (res == FR_OK)
    {
        dj_new.fs = dj_old.fs;
        res = follow_path (&dj_old, path_old);  /* Check old object */
        if (_FS_RPATH && res == FR_OK && (dj_old.fn[NS] & NS_DOT))
            res = FR_INVALID_NAME;
    }
    if (res != FR_OK)
        LEAVE_FF (dj_old.fs, res);  /* The old object is not found */

    if (!dj_old.dir)
        LEAVE_FF (dj_old.fs, FR_NO_FILE);   /* Is root dir? */
    mem_cpy (buf, dj_old.dir + DIR_Attr, 21);   /* Save the object information */

    mem_cpy (&dj_new, &dj_old, sizeof (DIR));
    res = follow_path (&dj_new, path_new);  /* Check new object */
    if (res == FR_OK)
        res = FR_EXIST;         /* The new object name is already existing */
    if (res == FR_NO_FILE)
    {                           /* Is it a valid path and no name collision? */
        res = dir_register (&dj_new);   /* Register the new object */
        if (res == FR_OK)
        {
            dir = dj_new.dir;   /* Copy object information into new entry */
            mem_cpy (dir + 13, buf + 2, 19);
            dir[DIR_Attr] = buf[0] | AM_ARC;
            dj_old.fs->wflag = 1;
            if (dir[DIR_Attr] & AM_DIR)
            {                   /* Update .. entry in the directory if needed */
                dw = clust2sect (dj_new.fs,
                                 (DWORD) LD_WORD (dir +
                                                  DIR_FstClusHI) | LD_WORD (dir
                                                                            +
                                                                            DIR_FstClusLO));
                if (!dw)
                {
                    res = FR_INT_ERR;
                }
                else
                {
                    res = move_window (dj_new.fs, dw);
                    dir = dj_new.fs->win + 32;
                    if (res == FR_OK && dir[1] == '.')
                    {
                        dw = (dj_new.fs->fs_type == FS_FAT32 &&
                              dj_new.sclust ==
                              dj_new.fs->dirbase) ? 0 : dj_new.sclust;
                        ST_WORD (dir + DIR_FstClusLO, dw);
                        ST_WORD (dir + DIR_FstClusHI, dw >> 16);
                        dj_new.fs->wflag = 1;
                    }
                }
            }
            if (res == FR_OK)
            {
                res = dir_remove (&dj_old); /* Remove old entry */
                if (res == FR_OK)
                    res = sync (dj_old.fs);
            }
        }
    }

    LEAVE_FF (dj_old.fs, res);
}

#endif /* !_FS_READONLY */
#endif /* _FS_MINIMIZE == 0 */
#endif /* _FS_MINIMIZE <= 1 */
#endif /* _FS_MINIMIZE <= 2 */

/*-----------------------------------------------------------------------*/

/* Forward data to the stream directly (Available on only _FS_TINY cfg)  */

/*-----------------------------------------------------------------------*/
#if _USE_FORWARD && _FS_TINY

FRESULT f_forward (FIL * fp,    /* Pointer to the file object */
                   UINT (*func) (const BYTE *, UINT),   /* Pointer to the streaming function */
                   UINT btr,    /* Number of bytes to forward */
                   UINT * bf    /* Pointer to number of bytes forwarded */
    )
{
    FRESULT res;
    DWORD remain, clst, sect;
    UINT rcnt;

    *bf = 0;

    res = validate (fp->fs, fp->id);    /* Check validity of the object */
    if (res != FR_OK)
        LEAVE_FF (fp->fs, res);
    if (fp->flag & FA__ERROR)   /* Check error flag */
        LEAVE_FF (fp->fs, FR_INT_ERR);
    if (!(fp->flag & FA_READ))  /* Check access mode */
        LEAVE_FF (fp->fs, FR_DENIED);

    remain = fp->fsize - fp->fptr;
    if (btr > remain)
        btr = (UINT) remain;    /* Truncate btr by remaining bytes */

    for (; btr && (*func) (NULL, 0);    /* Repeat until all data transferred or stream becomes busy */
         fp->fptr += rcnt, *bf += rcnt, btr -= rcnt)
    {
        if ((fp->fptr % SS (fp->fs)) == 0)
        {                       /* On the sector boundary? */
            if (fp->csect >= fp->fs->csize)
            {                   /* On the cluster boundary? */
                clst = (fp->fptr == 0) ?    /* On the top of the file? */
                    fp->org_clust : get_fat (fp->fs, fp->curr_clust);
                if (clst <= 1)
                    ABORT (fp->fs, FR_INT_ERR);
                if (clst == 0xFFFFFFFF)
                    ABORT (fp->fs, FR_DISK_ERR);
                fp->curr_clust = clst;  /* Update current cluster */
                fp->csect = 0;  /* Reset sector address in the cluster */
            }
            fp->csect++;        /* Next sector address in the cluster */
        }
        sect = clust2sect (fp->fs, fp->curr_clust); /* Get current data sector */
        if (!sect)
            ABORT (fp->fs, FR_INT_ERR);
        sect += fp->csect - 1;
        if (move_window (fp->fs, sect)) /* Move sector window */
            ABORT (fp->fs, FR_DISK_ERR);
        fp->dsect = sect;
        rcnt = SS (fp->fs) - (WORD) (fp->fptr % SS (fp->fs));   /* Forward data from sector window */
        if (rcnt > btr)
            rcnt = btr;
        rcnt = (*func) (&fp->fs->win[(WORD) fp->fptr % SS (fp->fs)], rcnt);
        if (!rcnt)
            ABORT (fp->fs, FR_INT_ERR);
    }

    LEAVE_FF (fp->fs, FR_OK);
}
#endif /* _USE_FORWARD */

#if _USE_MKFS && !_FS_READONLY

/*-----------------------------------------------------------------------*/

/* Create File System on the Drive                                       */

/*-----------------------------------------------------------------------*/
#define N_ROOTDIR	512         /* Multiple of 32 and <= 2048 */
#define N_FATS		1           /* 1 or 2 */
#define MAX_SECTOR	131072000UL /* Maximum partition size */
#define MIN_SECTOR	2000UL      /* Minimum partition size */

FRESULT f_mkfs (BYTE drv,       /* Logical drive number */
                BYTE partition, /* Partitioning rule 0:FDISK, 1:SFD */
                WORD allocsize  /* Allocation unit size [bytes] */
    )
{
    static const DWORD sstbl[] =
        { 2048000, 1024000, 512000, 256000, 128000, 64000, 32000, 16000, 8000,
4000, 0 };
    static const WORD cstbl[] =
        { 32768, 16384, 8192, 4096, 2048, 16384, 8192, 4096, 2048, 1024, 512 };
    BYTE fmt, m, *tbl;
    DWORD b_part, b_fat, b_dir, b_data; /* Area offset (LBA) */
    DWORD n_part, n_rsv, n_fat, n_dir;  /* Area size */
    DWORD n_clst, d, n;
    WORD as;
    FATFS *fs;
    DSTATUS stat;

    /* Check validity of the parameters */
    if (drv >= _DRIVES)
        return FR_INVALID_DRIVE;
    if (partition >= 2)
        return FR_MKFS_ABORTED;

    /* Check mounted drive and clear work area */
    fs = FatFs[drv];
    if (!fs)
        return FR_NOT_ENABLED;
    fs->fs_type = 0;
    drv = LD2PD (drv);

    /* Get disk statics */
    stat = disk_initialize (drv);
    if (stat & STA_NOINIT)
        return FR_NOT_READY;
    if (stat & STA_PROTECT)
        return FR_WRITE_PROTECTED;
#if _MAX_SS != 512              /* Get disk sector size */
    if (disk_ioctl (drv, GET_SECTOR_SIZE, &SS (fs)) != RES_OK
        || SS (fs) > _MAX_SS)
        return FR_MKFS_ABORTED;
#endif
    if (disk_ioctl (drv, GET_SECTOR_COUNT, &n_part) != RES_OK ||
        n_part < MIN_SECTOR)
        return FR_MKFS_ABORTED;
    if (n_part > MAX_SECTOR)
        n_part = MAX_SECTOR;
    b_part = (!partition) ? 63 : 0; /* Boot sector */
    n_part -= b_part;
    for (d = 512; d <= 32768U && d != allocsize; d <<= 1) ; /* Check validity of the allocation unit size */
    if (d != allocsize)
        allocsize = 0;
    if (!allocsize)
    {                           /* Auto selection of cluster size */
        d = n_part;
        for (as = SS (fs); as > 512U; as >>= 1)
            d >>= 1;
        for (n = 0; d < sstbl[n]; n++) ;
        allocsize = cstbl[n];
    }
    if (allocsize < SS (fs))
        allocsize = SS (fs);

    allocsize /= SS (fs);       /* Number of sectors per cluster */

    /* Pre-compute number of clusters and FAT type */
    n_clst = n_part / allocsize;
    fmt = FS_FAT12;
    if (n_clst >= 0xFF5)
        fmt = FS_FAT16;
    if (n_clst >= 0xFFF5)
        fmt = FS_FAT32;

    /* Determine offset and size of FAT structure */
    switch (fmt)
    {
        case FS_FAT12:
            n_fat = ((n_clst * 3 + 1) / 2 + 3 + SS (fs) - 1) / SS (fs);
            n_rsv = 1 + partition;
            n_dir = N_ROOTDIR * 32 / SS (fs);
            break;
        case FS_FAT16:
            n_fat = ((n_clst * 2) + 4 + SS (fs) - 1) / SS (fs);
            n_rsv = 1 + partition;
            n_dir = N_ROOTDIR * 32 / SS (fs);
            break;
        default:
            n_fat = ((n_clst * 4) + 8 + SS (fs) - 1) / SS (fs);
            n_rsv = 33 - partition;
            n_dir = 0;
    }
    b_fat = b_part + n_rsv;     /* FATs start sector */
    b_dir = b_fat + n_fat * N_FATS; /* Directory start sector */
    b_data = b_dir + n_dir;     /* Data start sector */

    /* Align data start sector to erase block boundary (for flash memory media) */
    if (disk_ioctl (drv, GET_BLOCK_SIZE, &n) != RES_OK)
        return FR_MKFS_ABORTED;
    n = (b_data + n - 1) & ~(n - 1);
    n_fat += (n - b_data) / N_FATS;
    /* b_dir and b_data are no longer used below */

    /* Determine number of cluster and final check of validity of the FAT type */
    n_clst = (n_part - n_rsv - n_fat * N_FATS - n_dir) / allocsize;
    if ((fmt == FS_FAT16 && n_clst < 0xFF5)
        || (fmt == FS_FAT32 && n_clst < 0xFFF5))
        return FR_MKFS_ABORTED;

    /* Create partition table if needed */
    if (!partition)
    {
        DWORD n_disk = b_part + n_part;

        mem_set (fs->win, 0, SS (fs));
        tbl = fs->win + MBR_Table;
        ST_DWORD (tbl, 0x00010180); /* Partition start in CHS */
        if (n_disk < 63UL * 255 * 1024)
        {                       /* Partition end in CHS */
            n_disk = n_disk / 63 / 255;
            tbl[7] = (BYTE) n_disk;
            tbl[6] = (BYTE) ((n_disk >> 2) | 63);
        }
        else
        {
            ST_WORD (&tbl[6], 0xFFFF);
        }
        tbl[5] = 254;
        if (fmt != FS_FAT32)    /* System ID */
            tbl[4] = (n_part < 0x10000) ? 0x04 : 0x06;
        else
            tbl[4] = 0x0c;
        ST_DWORD (tbl + 8, 63); /* Partition start in LBA */
        ST_DWORD (tbl + 12, n_part);    /* Partition size in LBA */
        ST_WORD (tbl + 64, 0xAA55); /* Signature */
        if (disk_write (drv, fs->win, 0, 1) != RES_OK)
            return FR_DISK_ERR;
        partition = 0xF8;
    }
    else
    {
        partition = 0xF0;
    }

    /* Create boot record */
    tbl = fs->win;              /* Clear buffer */
    mem_set (tbl, 0, SS (fs));
    ST_DWORD (tbl + BS_jmpBoot, 0x90FEEB);  /* Boot code (jmp $, nop) */
    ST_WORD (tbl + BPB_BytsPerSec, SS (fs));    /* Sector size */
    tbl[BPB_SecPerClus] = (BYTE) allocsize; /* Sectors per cluster */
    ST_WORD (tbl + BPB_RsvdSecCnt, n_rsv);  /* Reserved sectors */
    tbl[BPB_NumFATs] = N_FATS;  /* Number of FATs */
    ST_WORD (tbl + BPB_RootEntCnt, SS (fs) / 32 * n_dir);   /* Number of rootdir entries */
    if (n_part < 0x10000)
    {                           /* Number of total sectors */
        ST_WORD (tbl + BPB_TotSec16, n_part);
    }
    else
    {
        ST_DWORD (tbl + BPB_TotSec32, n_part);
    }
    tbl[BPB_Media] = partition; /* Media descripter */
    ST_WORD (tbl + BPB_SecPerTrk, 63);  /* Number of sectors per track */
    ST_WORD (tbl + BPB_NumHeads, 255);  /* Number of heads */
    ST_DWORD (tbl + BPB_HiddSec, b_part);   /* Hidden sectors */
    n = get_fattime ();         /* Use current time as a VSN */
    if (fmt != FS_FAT32)
    {
        ST_DWORD (tbl + BS_VolID, n);   /* Volume serial number */
        ST_WORD (tbl + BPB_FATSz16, n_fat); /* Number of secters per FAT */
        tbl[BS_DrvNum] = 0x80;  /* Drive number */
        tbl[BS_BootSig] = 0x29; /* Extended boot signature */
        mem_cpy (tbl + BS_VolLab, "NO NAME    FAT     ", 19);   /* Volume lavel, FAT signature */
    }
    else
    {
        ST_DWORD (tbl + BS_VolID32, n); /* Volume serial number */
        ST_DWORD (tbl + BPB_FATSz32, n_fat);    /* Number of secters per FAT */
        ST_DWORD (tbl + BPB_RootClus, 2);   /* Root directory cluster (2) */
        ST_WORD (tbl + BPB_FSInfo, 1);  /* FSInfo record offset (bs+1) */
        ST_WORD (tbl + BPB_BkBootSec, 6);   /* Backup boot record offset (bs+6) */
        tbl[BS_DrvNum32] = 0x80;    /* Drive number */
        tbl[BS_BootSig32] = 0x29;   /* Extended boot signature */
        mem_cpy (tbl + BS_VolLab32, "NO NAME    FAT32   ", 19); /* Volume lavel, FAT signature */
    }
    ST_WORD (tbl + BS_55AA, 0xAA55);    /* Signature */
    if (SS (fs) > 512U)
    {
        ST_WORD (tbl + SS (fs) - 2, 0xAA55);
    }
    if (disk_write (drv, tbl, b_part + 0, 1) != RES_OK)
        return FR_DISK_ERR;
    if (fmt == FS_FAT32)
        disk_write (drv, tbl, b_part + 6, 1);

    /* Initialize FAT area */
    for (m = 0; m < N_FATS; m++)
    {
        mem_set (tbl, 0, SS (fs));  /* 1st sector of the FAT  */
        if (fmt != FS_FAT32)
        {
            n = (fmt == FS_FAT12) ? 0x00FFFF00 : 0xFFFFFF00;
            n |= partition;
            ST_DWORD (tbl, n);  /* Reserve cluster #0-1 (FAT12/16) */
        }
        else
        {
            ST_DWORD (tbl + 0, 0xFFFFFFF8); /* Reserve cluster #0-1 (FAT32) */
            ST_DWORD (tbl + 4, 0xFFFFFFFF);
            ST_DWORD (tbl + 8, 0x0FFFFFFF); /* Reserve cluster #2 for root dir */
        }
        if (disk_write (drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
        mem_set (tbl, 0, SS (fs));  /* Following FAT entries are filled by zero */
        for (n = 1; n < n_fat; n++)
        {
            if (disk_write (drv, tbl, b_fat++, 1) != RES_OK)
                return FR_DISK_ERR;
        }
    }

    /* Initialize Root directory */
    m = (BYTE) ((fmt == FS_FAT32) ? allocsize : n_dir);
    do
    {
        if (disk_write (drv, tbl, b_fat++, 1) != RES_OK)
            return FR_DISK_ERR;
    } while (--m);

    /* Create FSInfo record if needed */
    if (fmt == FS_FAT32)
    {
        ST_WORD (tbl + BS_55AA, 0xAA55);
        ST_DWORD (tbl + FSI_LeadSig, 0x41615252);
        ST_DWORD (tbl + FSI_StrucSig, 0x61417272);
        ST_DWORD (tbl + FSI_Free_Count, n_clst - 1);
        ST_DWORD (tbl + FSI_Nxt_Free, 0xFFFFFFFF);
        disk_write (drv, tbl, b_part + 1, 1);
        disk_write (drv, tbl, b_part + 7, 1);
    }

    return (disk_ioctl (drv, CTRL_SYNC, (void *)NULL) ==
            RES_OK) ? FR_OK : FR_DISK_ERR;
}

#endif /* _USE_MKFS && !_FS_READONLY */

#if _USE_STRFUNC

/*-----------------------------------------------------------------------*/

/* Get a string from the file                                            */

/*-----------------------------------------------------------------------*/
char *f_gets (char *buff,       /* Pointer to the string buffer to read */
              int len,          /* Size of string buffer */
              FIL * fil         /* Pointer to the file object */
    )
{
    int i = 0;
    char *p = buff;
    UINT rc;

    while (i < len - 1)
    {                           /* Read bytes until buffer gets filled */
        f_read (fil, p, 1, &rc);
        if (rc != 1)
            break;              /* Break when no data to read */
#if _USE_STRFUNC >= 2
        if (*p == '\r')
            continue;           /* Strip '\r' */
#endif
        i++;
        if (*p++ == '\n')
            break;              /* Break when reached end of line */
    }
    *p = 0;
    return i ? buff : NULL;     /* When no data read (eof or error), return with error. */
}

#if !_FS_READONLY
#include <stdarg.h>

/*-----------------------------------------------------------------------*/

/* Put a character to the file                                           */

/*-----------------------------------------------------------------------*/
int f_putc (int chr,            /* A character to be output */
            FIL * fil           /* Ponter to the file object */
    )
{
    UINT bw;
    char c;

#if _USE_STRFUNC >= 2
    if (chr == '\n')
        f_putc ('\r', fil);     /* LF -> CRLF conversion */
#endif
    if (!fil)
    {                           /* Special value may be used to switch the destination to any other device */
        /*  put_console(chr);   */
        return chr;
    }
    c = (char)chr;
    f_write (fil, &c, 1, &bw);  /* Write a byte to the file */
    return bw ? chr : EOF;      /* Return the result */
}

/*-----------------------------------------------------------------------*/

/* Put a string to the file                                              */

/*-----------------------------------------------------------------------*/
int f_puts (const char *str,    /* Pointer to the string to be output */
            FIL * fil           /* Pointer to the file object */
    )
{
    int n;

    for (n = 0; *str; str++, n++)
    {
        if (f_putc (*str, fil) == EOF)
            return EOF;
    }
    return n;
}

/*-----------------------------------------------------------------------*/

/* Put a formatted string to the file                                    */

/*-----------------------------------------------------------------------*/
int f_printf (FIL * fil,        /* Pointer to the file object */
              const char *str,  /* Pointer to the format string */
              ...               /* Optional arguments... */
    )
{
    va_list arp;
    UCHAR c, f, r;
    ULONG val;
    char s[16];
    int i, w, res, cc;

    va_start (arp, str);

    for (cc = res = 0; cc != EOF; res += cc)
    {
        c = *str++;
        if (c == 0)
            break;              /* End of string */
        if (c != '%')
        {                       /* Non escape cahracter */
            cc = f_putc (c, fil);
            if (cc != EOF)
                cc = 1;
            continue;
        }
        w = f = 0;
        c = *str++;
        if (c == '0')
        {                       /* Flag: '0' padding */
            f = 1;
            c = *str++;
        }
        while (c >= '0' && c <= '9')
        {                       /* Precision */
            w = w * 10 + (c - '0');
            c = *str++;
        }
        if (c == 'l')
        {                       /* Prefix: Size is long int */
            f |= 2;
            c = *str++;
        }
        if (c == 's')
        {                       /* Type is string */
            cc = f_puts (va_arg (arp, char *), fil);

            continue;
        }
        if (c == 'c')
        {                       /* Type is character */
            cc = f_putc (va_arg (arp, int), fil);

            if (cc != EOF)
                cc = 1;
            continue;
        }
        r = 0;
        if (c == 'd')
            r = 10;             /* Type is signed decimal */
        if (c == 'u')
            r = 10;             /* Type is unsigned decimal */
        if (c == 'X')
            r = 16;             /* Type is unsigned hexdecimal */
        if (r == 0)
            break;              /* Unknown type */
        if (f & 2)
        {                       /* Get the value */
            val = (ULONG) va_arg (arp, long);
        }
        else
        {
            val =
                (c == 'd') ? (ULONG) (long)va_arg (arp,
                                                   int) : (ULONG) va_arg (arp,
                                                                          unsigned
                                                                          int);
        }
        /* Put numeral string */
        if (c == 'd')
        {
            if (val & 0x80000000)
            {
                val = 0 - val;
                f |= 4;
            }
        }
        i = sizeof (s) - 1;
        s[i] = 0;
        do
        {
            c = (UCHAR) (val % r + '0');
            if (c > '9')
                c += 7;
            s[--i] = c;
            val /= r;
        } while (i && val);
        if (i && (f & 4))
            s[--i] = '-';
        w = sizeof (s) - 1 - w;
        while (i && i > w)
            s[--i] = (f & 1) ? '0' : ' ';
        cc = f_puts (&s[i], fil);
    }

    va_end (arp);
    return (cc == EOF) ? cc : res;
}

#endif /* !_FS_READONLY */
#endif /* _USE_STRFUNC */
